AWS has identified suspicious activity on my account.

I'm using it for the first time in 2 years. That's the suspicious activity.

having an AWS account is suspicious in the first place, IMHO

Ha, this so reminds me of how Rachel got a call from the bank, checking on unusual activity 😁[FRIENDS]

Do you think there’s an email to themselves when an account has suspiciously low usage?

I think that's good.

Lots of people have inactive accounts from years ago - with bad passwords - they are potential targets to be taken over and misused.

Entirely reasonable you get a notification if you log in for the first time in years, imo.