Hello,
I am Alex Shopov - the coordinator of the Bulgarian translation team.
I have a very privacy conscious contributor that wants to be known only by their handle and email. I want to check that it is ok for the GNOME project.
My personal opinion is that it is indeed OK and this is no different compared to the general case: Even if a contributor gives me a name - I do not verify it, I do not ask for ID document, I do not go around asking people to confirm the identity.
In many cases I may never see the translator in person.
Additionally I could not find anything contradicting this in the Code of Conduct , the docs on translation and the Privacy Policy.
I always check submitted translations for problems and improvements and thus am not concerned about foul play (and I have never ever had such a case). I just want to confirm that from the GNOME’s project side this is OK.