Add Cree languages

There is no need to go through the Incubator since the Cree Wikipedia already exist at cr.wp. The cr code is already "activated" on translatewiki, however, it doesn't really make sense to translate the interface under the code cr which is a macro-language code, because it will be done in one of the dialects (which all have their own language ISO code) or even in a mix of dialects if translators from a different language community come to translate. The Cree community has decided it doesn't worth nor make sense to divide their Wikipedias in different projects and are happy with the work in progress on cr.wp to support the different Cree languages/dialects. There is no intent to have atj.wp or crl.wp anytime soon, and the portals you linked are not incubators, they are there to stay as they are and to grow. That being said, it doesn't mean users can't translate and use the mediawiki interface in their own language. I'm not sure why you ask about the activity level on Wikimedia, how is that a pre-requisite to have a language supported on translatewiki? For potential translators, atj just finished the normalisation of its orthograph and is undertaking pedagogic projects across their schools to develop Wikipedia and I will point them to translatewiki as well, for crj there is a very motivated contributor that will be interested in doing some translations of the interface as well.

Fallback would be English for most Cree languages and French for some (atj speakers for example mainly have French as second language). That being said we could make up a more elaborate "fallback tree". For example I asked for crj in the first post, but crl is very similar to crj (in fact the main differences are with pronunciation, they write the language pretty much the same according to a Cree language consultant and Eastern Cree speaker).

P.S. Your links to the incubator don't work, I think you in fact tried to link the Cree Wikipedia.

Incubator for crj now links w:cr:ᑳ_ᐋᐸᐦᐄᔥᑌᒡ:ᐃᔨᔨᐤ_ᐊᔨᒧᐧᐃᓐ, where a mix of Latn and Cans is used. Ethnologue seems to consider Latin as the main script. Do we really need two parallel language codes, one for each script, and who is going to translate which one?