Unnecessary RDS PostgreSQL 11 Upgrade Notices

Hi everyone,

I upgraded all of my PostgreSQL 11 instances to 15+ earlier this month, but I am still getting AWS emails that begin with "You are receiving this message because you have one or more Amazon RDS for PostgreSQL database instances running major version 11".

Is anyone else getting these? Are they safe to ignore? Hopefully it's just some idiosyncrasy in the AWS notification system, but I'm still a bit concerned.

Thanks!