I don't expect many EU apps to bundle Chrome because they can't use it outside the EU and the benefits of bundling a different browser engine for in-app browsing would be limited for the types of basic browsing that is typically done inside a non-browser app. Additionally, Apple is imposing additional requirements on apps that embed alternative browser engines, including requiring apps to be updated within 15 business days of a browser engine update and requiring the app to only be available in the EU.

As a result, I would expect Chrome/Firefox/Edge/Opera to ship their own browser engines on iOS but am doubtful that many other apps will embed Chromium/Gecko with the possible exception of apps that only operate in the EU.