The Dragon Lord
Face looks the same for all characters in these games. I don't see any difference in the faces of Lillie and Gladion for instance.
Not really. Lillie and Gladion have completely different eyes. Gladion has eyes with sharp angles and thick eyebrows, while Lillie has round eyes with big pupils. I'll admit that sometimes the low resolution 3D models makes some faces look the same, but the eyes are almost always distinguishing features. In this case, the eyes of both protagonists are exactly the same.
Let's be real here. The only thing we actually know of these games is that they'll come out in November 2017 on the 3DS, that they're Alola Games, and that they have new forms of some sort for Lunala and Solgaleo (not counting event-only Lycanroc as game content as it's event only). Because they've told us literally nothing yet. The only thing we got is a video with a few seconds of footage which could have been edited and put together in all sorts of ways. They show us the house where the protagonist in SM lived, and people simply make out of that that the player character in USUM must live there as well, even though that's never directly stated.
Technically true. But there is literally no reason to doubt that these are same characters. I don't even care about the house the part. You're right, the house could be any number of things, but that's not the definitive evidence. What's definitive is that we've seen the protagonist, and it's the exact same person wearing different clothes, which isn't unusual by any means, given the history of third versions.
People see empty stands in SM and turn that into "Gyms are coming". And people see that USUM and SM have similar names so they turn that into "USUM are sequals because BW2 re-used the names too".
Okay, so people speculate, what does that have to with whether or not the playable character is the same person?