Apple was clear that they were offering the safety of a walled garden from the start.

Apple didn't lie about supporting a user's freedom to run anything they like, only to execute a rug pull after they successfully drove the other open options out of the marketplace.

Which increases the limit to whatever time is left on your current payment period. After which the app will stop working and need to be reinstalled by an authenticated developer who has a current Apple Developer Subscription.

EDIT: Edited the above which previously said 90 days incorrectly. Not sure where my brain pulled that from but I posted the correct details here prior: https://news.ycombinator.com/item?id=45743615

Notably if you install a month before your subscription expires you need to reinstall the app in 1 month.

You can refresh them. SideStore[1] does that automatically out of the box (no computer needed) but there are Shortcuts to do that too.

[1] https://docs.sidestore.io/docs/faq#what-is-sidestore