Enable aae: Arbërisht
No, do not remove the alert as long as it is not enabled (and notably don't allow the link to the translate UI as it will NOT select the correct target language and can damage the translation of other languages: if you follow a link using an sdaibled language, the Translate UI will open only for translating to your currently selected and enabled user language, not the one you expected!).
I provided you a link above showing the actual status. Only a site admin can activate the Translation UI (and it will instantly be visible on Special:ActiveLanguages/aae). Only at that time, the alert can be dropped from the portal (there's still no way in the wiki to test automatically if a language is enabled or not, so the portal page still has to be tweaked manually.)
Still you can register on the portal in the list of translators, and can also add the language as well to your babel box on your user page (but your level 2 on it may not be sufficient for the site admin, nespacially if you work alone: invite other interested users to join your effort here or on the Wikimedia Incubator by creating an account here, and register themselves in the portal after filling in their user box; this is not necessary for new translators once the language is enabled and actively maintained with a active community somewhere to discuss it).
Also look at the requirements for an Incubator to succeed., and they are checked as well on https://codelookup.toolforge.org/aae (these conditions, summarized in https://incubator.wikimedia.org/wiki/Wp/aae, are those from Wikimedia, and are separate of conditions for enableing the language on translatewiki.net; they are not decided by the same admins, but a language enabled in Wikiemdia will generally be enabled here very fast).
See also guidelines and policies documented on Translatewiki.net languages (some infos may be old and may eventually have changed, but they are still globally relevant even they could have been relaxed or enforced with new requirements, the site admins will decide what to do after consulting relevant parties for each target project, notably those for Wikimedia wikis or for the genral translation of the Mediawiki UI).
Very well. I did as you said: I am now on the list of translators, I elevated my babel box to level 3, and I invited a native Arbëresh speaker to create accounts here and on Wikimedia in order to help my translation efforts. I also foresaw the requirements you mentioned, that is why I came here in the first place. Now my question is: Who is able to enable aae translations and where can I submit such a request?
This is the right place. Normally a site admin (probably from bureaucrats, including possibly Trizek (WMF) who works for the Wikimedia Foundation in relation with communities) should see your request here and reply. Do what you can in your new Incubator with users you can involve to the project, to show their support. I just gave suggestions in order for you to be convincing. I cannot do anything more
As well you can add your request to Wikimedia's language team (the relevant links are in the entry page of your Incubator), may be they'll create a task in Wikimedia's Phabricator if other Wikimedia users are convincing. And outside Wikimedia, you may find other projects for their wikis or software or site projects that are already using Translatewiki.net, that could have their own request with their own supporting users. You may also find relevant support from local schools or linguistic departments of universities in Italy, or from Italian public libraries for their archives, books or sponsored cultural programs.
So collect as many relevant sources that may be useful (you can do that in your Incubator, or inside other wikimedia wikis, such as Italian or Albanian Wikisource in dedicated subsections/categories/portals and wikiprojects/talks). You may also find open-sourced terminologic lists, social network groups or channels, and local associations or user groups supporting this development. Add as many references as you can and start organizing them, with the help of other contributors that may want to help you. And try to develop a "testbed" with some examplar contents (you're not required to develop a fully functional Wikipedia covering all topics: start simple, focusing first on some important topics that are relevant more specifically for that language and how it differentiates from standard Albanian, or how it evolved in contact with Italian (grammar, vocabulary, orthography, phonetics, some articles about most famous artists or photos and facsimiles of cultural creations...).
Also find the help of graphic designers for relevant maps on Wikimedia Commons (modern or historical aspects: even if you are not a great graphist, make some good drafts: you may create a snapshot from another basemap and add annotations and import some PNG image, ask on Wikimedia Commons helps to create better looking maps, and don't forget to provide some basic translations, notably in Italian or English, so that what you'll create will be found by other people). Finally you can already add data in Wikidata. All that's is a lot of work, and of course you cannot do everything alone, so invite people and welcome them to help you (if you're alone, your work is at risk of being damaged or deleted in Wikimedia sites and you may be exposed to offensive attacks because what you'll have done will not be "perfect" in their opinion). This initial setup will be long and hard, and this is in fact general for all minority languages, until a sufficient consensus is reached at least for some basic stable structure.
In the Incubator, don't focus much on presentation (navboxes, templates...: you may prefill some data but hide them to avoid many "red links" that will complicate the navigation) or complete coverage of any topic (except a few examplar articles/pages: for example, articles in Arbërisht about countries outside its development area is not essential, and you may just have a few stub articles for Europe, or the Mediterranean Sea, and for other languages like Italian or Standard Albanian, or their related regional dialects: these stubs should just be there to help organize and correlate the useful content you want to promote). It is much more important to focus on content organisation (and easy navigation) and on relevant sources. Making that "beautiful" can be done later, however avoid long vertical lists without any useful content (lists can be placed in other pages/subpages: it is more important to show normal paragraphs in the language itself): stay focused, this must be a useful and relevant demonstration.