For the sake of additional data points here (using build 2025.2.1 (394)):

-The video players in Avatar Testing Chamber and Cozy Boat also display this behavior, including the pink 'broken/missing shader/texture' part over the controls. Neither of these worlds have iOS specific builds.

-The player in Comfy Puzzles (VizVid) appears to be unable to play videos when it is in "video" mode as opposed to "stream" mode; the former mode gives an error of "Media cannot be played, maybe due to invalid format or region block" on the player status bar. Switching to "stream" mode does allow it to play, and it does so in the correct orientation, though, as noted in another feedback thread, there is no audio. This world DOES have an iOS-specific build.

-The player in Sovern's Chill Home is ProTV3 (currently showing as 3.0.0-beta.24.2) also plays videos in the correct orientation and doesn't require changing any sort of video/stream 'mode' switch. Of note, this player has 4 available quality settings (AVPro Best, AVPro Compatibility, Low Quality, and Unity Video); the first 3 all appear to play the video as expected (minus audio of course), while the 4th gives a nonspecific 'Unable to load video' error and switches back to the last quality setting that worked. There's also a weird thing when opening the selection drop-down menu where each option is simply labeled "Option"; I'll try to get a screenshot of that and open a different bug report on that though.

In my world '42 (Answer)' the video is not flipped.