Event Category

Does the tracking link event "Move to App (Link)" mean that the user has transitioned to the mobile application?

No, it means that the clicked tracking link's destination URL is a deep link. It is considered as a "Move to App (Link)" event even if the user is redirected to the marketplace or a website when the app is not installed. "Move to App (Link)" can be seen as "attempts to move to the app", not "actual moves to the app".

Move to App (Link)1,200"Deeplink Open (App)" + "(Move to App Store (Link)" + "Move to Google Play (Link)" + "Move to Web (Link)" = "Move to App (Link)"
Deeplink Open (App)600
Move to App Store (Link)200
Move to Google Play (Link)300
Move to Web (Link)100

For example, consider the case where the count for "Move to App (Link)" is 800. 500 users may have the app installed and properly redirected to a specific page in the app, while the other 300 users did not have the app installed and fallbacks to the app marketplace.

"Move to Web (Link)", "Move to App Store (Link)", "Move to Google Play (Link)" has the same count for attempts and actual moves.