To do this I think we will have to delete the redirection currently setup from https://translatewiki.net/w/i.php?title=User:Navhy&redirect=no to https://translatewiki.net/wiki/User:Iv%C3%A1ns. I will check with Niklas on whether this is OK to do and perform this deletion. Please confirm if this is OK with you.
It seems like that page is the default template for unavailable talk pages, for eg see: https://translatewiki.net/wiki/User_talk:AbijeetUnavailable
I don't think there is anything else that we can do here.
I already marked it to erase. It makes no sense a page of a user that no longer exists, now all the information is already passed to my new account. I want to erase every trace on the internet of my old name
Its not about no longer existing. If you take this URL - https://translatewiki.net/wiki/User_talk:ReplaceMe and replace the "ReplaceMe" part with any other string, you will still see the same page. Its a default template that appears for non-existent talk pages, irrespective of whether the user existed before or never existed.
But if there was never a user with that name, as you say, the page should not exist... I change the url to the page that requested the deletion and it still exists. Only admins can delete it.
It is very simple to press the delete button please, if another user comes later and wants to make an account the page will be created again, although it is unlikely...