I'm not clear on why Librem would need to add an in-app purchase option under app store guidelines, and their article doesn't really explain it either. App store guidelines on this topic are: > 3.1.3(f) Free Stand-alone Apps: Free apps acting as a stand-alone companion to a paid web based tool (eg. VOIP, Cloud Storage, Email Services, Web Hosting) do not need to use in-app purchase, provided there is no purchasing in…
"Even though Librem Tunnel is just part of the overall Librem One offering, because it’s part of a subscription service, Apple is requiring us to add the ability to sign up and pay for Librem One subscriptions within the Librem Tunnel app before they will allow updated versions into the App Store."
However, what you show seems to contradict that?
EDIT: If I were to guess, the flagging was an automated process, i.e. Apple flagged it and sent an automated email to Purism. Whether or not Purism tried to respond or not I do not know, but in the end they decided not to deal with it and pulled their app.