Just because Fallout 4 might take place in the Commonwealth, which it might not also, doesn't mean that it necessarily has to base the main story on the android revolution or even the Institute at all.
The Institute and the android storyline can just be a secondary theme done outside of the Main Quest. There is potentially a million different things they could do within the setting of the Commonwealth that has nothing to do with the specific location at all and that could be the same main theme in any other location from New York to Pango Pango.
If Fallout 4 does take place in the Commonwealth then I actually hope the main quest is not dealing with the droids. I hope that the Institute is actually like one of the major cities in the other games such as NCR or Megaton but not the focus of the game. I would actually love to visit post-apocalyptica Boston and stand amidst a major ruined city as one of the available locations.
No to Commonwealth DLC, I might enjoy an expansion but it isn't going to happen so I'm not going to even form the illusion it might.
Yeah, I don't know about an android revolution either, that little side quest wasn't that exciting and I only do it because it's quick and
is good.
Blade Runner and
I, Robot pretty much covered that anyway. As a non-main storyline I'd like to see people trying to restart the country and contributing to it, since that is where it started to begin with. I'd love to see Old Ironsides sailing around blasting things, maybe the flagship of a young Navy.
Major settlements should have hundreds of people. Rivet City wasn't all that big as far as population, as many security people as citizens. Then again, bustling streets would make it hard to find character's you need to interact with.