Well if comparing the S1R to the SL2, the SL2 had the arguably slightly better build by all accounts, (not that the S1R was shabby by any means), plus the badge and a nicer looking body, but otherwise, pretty much the same thing. Just half the price. And with a multi-angle rear screen vs the flat back of the camera which for my work is terrible.
I can't see any future S2R simply being a rebadged SL3 though, but I would be pretty stoked if it was as I'd love an SL3 other than on price.
It's probably the perfect camera for my needs as in:
Want, but can't afford a Hassie X2D, never mind the cost of the system with lenses.
Like the idea of a Fuji X100 but don't care for the lenses.
Like my A7RV and the lenses, but would rather have all 3 of my cameras within the same system for cross compatibility and my video needs are served with 2 LUMIX cameras and various lenses...so an S2R makes a whole load of sense to me!