I think that maybe it's because hacks are getting popular now, so there are more accounts to be verified.
I don't know if it's the same with Mario Kart Tour, but I remember that when I first hacked Pokemon GO (shortly after it was release) I was banned almost immediately. When I tried to hack it the second time (a long time later) I got banned more or less 1 month after.
Edit: or maybe verifications are automatic and it's just random picking lol.