Most of Meridanium and Praetorium's cutscenes can be viewed in the Unending Journey (although they're scattered between 'main scenario' and 'duties'), plus a number of small scenes don't appear. A little known aspect of it is also your party appears beside you and even have little gestures and movements in the background when actually viewing the scenes as part of the dungeons, while in the Undending Journey naturally this doesn't occur, so a lot of context is lost.

The problem is, SE underestimated human nature being selfish and impatient, and thought that players would patiently view each cutscene at the same time. Sadly this did not turn out to be the case. Luckily SE listened to players and thus later dungeons like Heavensward's final dungeon are structured much differently, but it still leaves CM and Prae like this.

As others have already stated, try running it undermanned with a couple of friends and ask if you can watch the cutscenes.