In the documentation for Developing a Great App Clip - https://developer.apple.com/documentation/app_clips/developing_a_great_app_clip under Understand How Users Launch App Clips it says users launch app clips by tapping a link that someone has shared in the Messages app.
What about links from other places? What about a link from Mail.app or from a different messaging app or from web search result? Do App Clip links behave the same as Universal Links?