Will the 1DX Mark III have IBIS?

A new rumor from Canon Rumors suggests that there still is the possibility that the 1DX Mark III will have IBIS.  From Canon Rumor's source who claims to have shot with the camera, they state that the new flagship DSLR does indeed have in-body stabilization and that all future Canon ILC cameras will have the feature as well.

While the development announcement and further information have not really stated that it won't have IBIS, you would think that such an important feature would have made it on the list of features that Canon would have pre-announced. 

While there are certainly some pros to having IBIS in Canon's cameras, stabilizing primes is very important, it would also be a critical feature to have for shooting video with the 1DX Mark III. But would the 1 series camera see that much benefit to IBIS?  Predominantly images are taken with IS capable lenses and at faster shutter speeds.  Then we have the issue of IBIS not stabilizing the optical viewfinder and also the autofocus sensor.

As far as the IBIS featured on all future DSLR's that is similarly problematic. We've also seen many IBIS and IS patents to show that Canon is seriously looking at implementing a hybrid IS solution, however that solution because of the information that needs to flow back and forth between the lens and the camera body, doesn't lend itself well to the EF mount, because the communication speed for the EF mount was designed in the early '80s and it doesn't support a very fast transmission of data by today's standards, but was quite fast for the time.  With the EF mount's slow communication speed, and lenses that are incapable of transmission IS positional data back to the camera body, it seems if IBIS would be implemented on the EF mount for Canon DSLR's that it would be limited in functionality as compared to the RF mount IBIS.

Time will tell.