I got this from their customer service. I thought I was on 15.1 on my iPad, but wasn’t. I fly on Sunday at noon and will let you know. Keeping one phone on 15.0.2, the other phone on 14.8.1, and iPad on 15.1. Will let you all know!
The issue you're seeing isn't related to our connectivity solution; the problem has impacted all Apple customers that attempt to play DRM content with a Safari Browser. You'll need to upgrade your iPad to iOS 15.1 before your next flight. Any Apple devices attempting to view Wireless IFE content when running iOS 15, 15.01, or 15.02 will result in the end-user receiving an error that this user witnessed during his flight. Let us know if this works.