A popular Apple blogger has accidentally caused a number of people to think that the browser choice screen will be shown to users in the EU on every operating system update. That is not the case. The browser choice screen will be shown once per device according to Apple itself:
About the browser choice screen in the EU - Support - Apple Developer
iOS 17.4 introduces a new choice screen that provides EU users an additional way to choose a default web browser from a list of options.
(developer.apple.com)