Mostly. I have been able to partially recover an account by renaming username back to what it was prior to being anonymized and reattaching the user email and reactivate account. Seems to keep original password. But all other things are gone, profile pic, birthday if entered. I had to explore this when I had a Moderator go off the rails.
It is a pain and not simple.The only thing is in posts where the user may have posted may have details in a post. Now if that was in a Personal message maybe not a big deal.
I believe the team has said though this is within gpdr compliance.
If a member requests to be anonymized likely good to ask them to scan their posts and if necessary flag them for deletion. Ie posts with uploaded pictures of the poster for example.