I agree that closing the arena for certain games is a bad move. I'm personally only impacted on chess, not sure how many other games have had their arena shut down.
I play arena cause in casual play people don't play a lot or leave games etc. In arena people are just more serious about their game. I understand this comes with the occasional bad apple that decides to cheat. But honestly I wouldn't be able to tell the difference between a cheater and a just real strong player. If I lose I don't immediately suspect my opponent is a cheater, usually I just moved without thinking hehe.
I'm sure there are people who share my opinion but by closing chess arena you've closed off chess for me completely on BGA. And that's really sad. I don't mind putting up with an occasional (aledged) cheater. Instead of taking arena away for everyone, people who are upset about this should just not play chess in arena. Now they can't play arena anyway but the rest of us are "punished" aswell and it honestly doesn't solve anything for the people who were complaining. If anything it's more likely these cheaters will now move to casual play and ruin the games there for those complaining people.