Stories like that can work, but I feel like a majority of the time directors do that, it breaks up the flow too much and can kill momentum. Like @DoctorEncore said, the writers and Chris Pine's acting did a good job of trusting the viewer with the source material, resulting in a fun film.
I don't want my fantasy interspersed with scenes of a noob player (stand in for the unfamiliar audience) being surprised by a new mechanic and having other players explain it, or where the DM goes on a power trip. I've never heard anyone say Fred Savage was the best part of Princess Bride. It stops the story we are actually invested in dead in it's tracks.
I think it works best with low fantasy, like in the case of Jumanji, where there's less suspension of disbelief required. Switching back and forth from our reality to high fantasy is too jarring. But I'm open to opinions and movie recommendations where it works.