Sigma Fp is a great example how small a full frame camera body can be. Yes, it is only electronic shutter, but gives first glimpses of future. Lack of built-in EVF might mean something like eyesglasses (or shades for cooler look) integrated wireless EVF. This way you can see focus easily and do precise composition.
People who want something more than a phone, but don't want to pay too much, can get a superzoom "bridge" cameras. Convenience is high for these considering they are stand-alone cameras. Sensors like M43 and APS-C are losing their edge because of price drops and more compact bodies of full frames. If lenses are too big, there is always options to design very compact lenses for FF, but of course lose some optical quality. Then reasons for separated M43 or APS-C lens lines are going away when manufacturers are deciding new models which could just focus on FF and beyond.
Basically I mean that a future M43 or ASP-C could be just a lens choice for FF like compact lens (M43), medium lens (ASP-C) or big lens (full frame).
