It’s probable they stopped playing, their account was caught in a password leak and they reused password and were hijacked by some botfarm to be used for event vehicle grinding to resell on gaijin store.
That’s usually the case in other MMOs if you see an old or non-suspicious account banned for botting.
This is of course not an excuse and justification to be unbanned.
If you want more details regarding rules in chat i would recommend reading through the Code of Conduct (which honestly all players really should do, it isn’t even that long).
Great job, finally we have a fair game for 12 hours(After this, russian hacker updated ther data than those cheater come back;the majority of chiness cheater buy their cheat from russian)