Apple will require notarization for apps from third party app stores, and will disable updates for apps installed via third party app stores if staying outside EU
As far as I can tell this basically means that all apps must be approved by Apple to follow their "platform policies for security and privacy" even if publishing on a third party app store. They will also disable updating apps from third party app stores if you stay outside the EU for too long (even if you are a citizen of an EU...