To me it sounds more like the right move, Sony is not competitive on the dslr market, their offer is average, with half their lens range being some left over Minolta from the eighties.
Being successful with the A7 range, it seems only natural they concentrate on the E mount that is the camera that sells (speak A7 family) as well as their crop sensor evils that share the same mount.
Threat for Sony users that the E mount is abandoned as well ? That would means they quit making cameras, since they do not have a 3rd lens mount, and won't live out of compact cameras either.
IMO they put a cheap new A68 to quieten the small but obviously vocal group of A mount user, but it is a dead end anyway. The'll keep making adapters to mount the old A mount lenses on E mount cameras, same as Olympus did with the 4/3 versus Micro 4/3.