I actually agree with much of what you say here. That's what brings us right back to where all of this discussion started: the name of the game. To restate my point, if you're going to make a new game that significantly deviates from earlier games in a franchise, you should give it a new name, exactly like what Obsidian did by calling their game Fallout: New Vegas, and exactly how Larian itself did with its own franchise by calling their new game Divinity: Original Sin rather than Divinity 3. To have called Divinity: Original Sin Divinity 3 would have been false advertising, in my view.
I sort of see the point, though IMHO games, sequels and pretty much everything should use names and drop the numbering scheme as implies so many things, many of which are contradictory. Is it a continuation, a rehash, in the spirit of, the next book rather than the next chapter (which is what I sort of meant by continuation)...? Giving it a name might help stop those preconceptions. I tend to adapt after that initial "but that's not what I was expecting" but I can rant about it in the meantime. Then again, no matter what it's called you will get people who will assume and then object forever, e.g. TES:IV Oblivion being lambasted for not being TES:III Morrowind Part II in spite of the fact that it never said it was going to be and the name didn't imply anything other than it being the next Elder Scrolls game.