Am I reading it right that the original Free Tier had a quota of 45,000GB? That seems absurdly high and not very sustainable (hence the change I assume).
I guess someone has been backing up their movie collections to Gitlab or something.
I replaced it with a fixture that was 2GB of space characters, which compressed down to about 3KB. I know there's a canonical file bomb zip file that's under 1K but there's clever and then there's clever.
IMO GitLab does the wrong thing. They should have enforced those limits from the beginning. And if they didn't, they should've eaten those expenses or at least grandfathered old repos.
Why should they eat the expenses of abusive users? As well they clearly have and are finally taking action about preventing it. Your entire post seems extremely entitled to their money.