You are probably right, but then it means that there is a new version of the 50mp sensor. This wouldn't be surprising since the initial one is getting a bit old by Sony standards.
No way to tell if only AF was added to the sensor or whether it was improved in others way also. It wouldn't be surprising if it had been improved in other ways also.
As far as AF goes, it would make the traditional MF SLR pretty much irrelevant since on sensor AF would be all over the frame... 
Cheers,
Bernard
Sony always has a new version of everything

but somebody remarked that focus pixels can be created just with the help of the CFA stage of processing. With modern equipment that might mean single units can be run off ...
I think the A7 series now has focus just about anywhere, no?
As does the Canon A7 and 1DxII when filming, "probably".
Canon's implementation is supposed to be exemplary, but the Sony system seems to work.
Edmund