I suspect Canon of being all in as well, but having missed a deadline on a body - could it be the sensor that missed, and how far off is it? The existing EOS-R is probably the low-end model of a pair of bodies they were planning to release? The reason for that speculation is that the Canon lenses are too nice (and too high-spec) to really belong with a 6DII with an EVF.
If I had to guess what the "missing body" is, it's something like a mirrorless 5Ds, although with a somewhat improved sensor. It'll be a worthy competitor to the Z7 when it emerges.
The little 35mm macro makes sense with this body, and, while the 24-105 doesn't really, it fits with an established Canon pattern of "super-kit" lenses that are big, heavy and expensive for a kit lens, but also offer excellent image quality. The similar EF 24-105 is a common kit lens with both the 6DII and the 5DIV, and the smaller EF 24-70 f4 is much newer than the first version of the 24-105 - they went with only relatively large standard zooms for years on EF.
The two big, expensive lenses (a 50mm over 2 lbs for $2299, a 28-70 over 3 lbs for $2999, both extremely fast) make no sense with this body.
If we think of a body that makes sense with those lenses and the innovative adapters, it would probably be a bit bigger and heavier than the EOS R (more the size of the new Panasonics than the Z7), with 5D series build quality or better. Might it have IBIS? Priced around $4000? I haven't heard anything about such a body, but it makes sense with the lenses, and I can't see what else would...
At least my personal suspicion is that Canon was originally planning to release two bodies and four (or five) lenses to start - if there's a missing lens, it might be a 24-70 f4 (or variable aperture) that provides a lightweight companion to the EOS R.