Actually, this is happening at Mastodon as well.

The instance for which I created my account suddenly terminated its service, leaving me powerless to do anything.

However, when I search from other running instances of mastodon using my username at the time

I can still see the unimportant content posted back then.

I want to bury it in the dark, but since the instance was closed, it will remain as a zombie forever. Failure. #Mastodon