Hasselblad broke the 200 MP barrier with it, Olympus boosted the OM-D EM5II, now Pentax is offering Pixel Shift in its 1899,- Full Frame K-1.
Pixel Shift / Multishot. Yes, it's tripod only. Yes, it only makes sense, if your subject is static.
But, the A7*II has in-Body-Image-Stabilization, thus would probably (given the right software) be able to do this, too.
This is not just about resolution, but mainly about canceling out the bayer interpolation (resulting in more detail, better DR and lower noise even at ISO 100)
Please, Sony, pretty please... give us an App (I'd pay $100+ for it!) or a firmware upgrade.
I've started a request in Sonys "Join the Inspiration"-Community last December, maybe you want to join?