This has nothing to do with the Apple Card. Google loves suspending Ads accounts for doing any changes to their profiles. I've had to go through this BS at least 5 times.

Odds are this guy would've been banned no matter which card he switched to.

Given that smartprivacy pushes VPN stuff I wouldn't be surprised if this guy had been using a VPN to log into his Ads account, which would be a sure way to get your account fucked.