It would be nice to have a speaker on the upper side of iPad, and then iPad to auto-detect when you are watching a video content in the landscape mode. In addition, hopefully one day we will also get front-firing, rather than side-firing speakers.
I don't think this will ever happen unless they abandon the edge-to-edge glass, which I don't see happening any time soon.
...unless they figure out how to magically play sound through the glass or build it into a gap between the edge or something, but I'm just grasping at straws here.