I'm not sure... and I mean I really don't know, but I don't think these consumer electronics companies can survive catering to legacy lens geeks. Most of the public doesn't particularly care about that type of stuff.
Nex would have gone nowhere without it. Without Nex there would have been no A7 (it was cancelled twice as is) The legacy use gives you the Buzz of vocal camera experts. Make their old favorite lens work well and they will tell the world your camera is fantastic. Priceless.
Sony is making a killing on the A7 cameras and lenses which have incredible margins compared to Canikon stuff. This line has given the whole company the best year in many. See the quarterly report and refer the boost in operating capital.
It's only a matter of time before the EVIL cameras replace DSLRs for many or most pros, but it may take 10 years.
The APS-C EVIL market is already saturated. The real money will be in the gap between the Sony A7, which is very immature as a system, and the only true "systems" Canikon.
People need "a reason to buy". Sony knows what it is: "smaller", but their delivery is piecemeal to say the least. Leica did alot of interesting things with the SL, but it's huge, and can only get away with that because the M primes are tiny and the overall build of the SL is exquisite.
Here is what will make somebody a fortune:
FF Body 75% of the size of A7r2, BSI sensor, thin cover glass, 1500 shot battery, two cards, great SL level EVF, very wide short register mount. Slick build and highly programable firmware so profiles can be created. 4K video on one version: charge more for that one.
Be sure the buyer can use any lens like with the sony but again with thin cover so they really work. Don't worry you will still make a fortune because only your lenses will AF properly.
Development priority: make on-sensor PDAF follow focus well with your natives. Absolute must for sports and the large market of bird chasers. Start with the "holy trinity" 3 fast zooms. Pull out all stops to make them as small as possible. With your wide short mount it should be easy to reduce size and weight by 25% over current Canikon. Then fill the system ASAP up to 500/4 and with some exotic AF primes. Make them all as small as you possibly can, but at least 25 % less.
If you are Canikon of course you have a LAEA4 type adapter ready to AF your big lenses of the past.
Such a new system is entirely possible today, and pros would fall over themselves to buy in if it was done right.
Size matters. Size matters. Size is a reason to buy a new system. Sure there will be people who deny this. Then they will buy one too.
Leica created an entire system, spawned an industry and this forum with a single original priority: small size, high quality.