As a long time Canon (2 decades plus) and Fujifilm (a dozen years) photographer, I have some thoughts.
But first, we really should not be putting much stock in the source of the recent Fujifilm XT-6 rumors. Most of them are computer translations of a very strange post on a Vietnamese website, and there is no corroboration at all of the info there, much of which looks like a combination wishful thinking and already-likely updates for the future camera.
Most likely the Fujifilm camera will have an updated (and likely improved) version of the 40MP sensor, improved AF, other updates that would be expected with a new version, and possibly some ergonomic changes. Most people think that it is unlikely to be so different from the current XT-5 that owners of the current camera would be compelled to upgrade.
It is likely that Fujifilm will continue to improve their AF in the new camera. Fujifilm's current AF is fine, though the best from Canon, Nikon, and Sony is somewhat better.
Perhaps Fujifilm's biggest asset is its very large selection of excellent dedicated APS-C lenses No one else, and especially not Canon, has anything like it. Yes, you can put any Canon lens on their APS-C cameras, but still...
The XT line (and virtually Fujifilm lenses) continue to use the so-called "retro" interface with full manual controls including aperture rings, shutter speed, ISO, and EC knobs. If you like that — and as a long time photographer, I do for many purposes — Fujifim is where you find it.
The XT-5 is a very small camera, particularly for one that is so feature rich. It will be a challenge for Canon to compete with that.
Canon has one other small disadvantage with their implementation of APS-C. Cann uses a slightly smaller 1.6x crop factor sensor format, while Fujifilm uses the more standard 1.5x size — a small difference, but still a difference.
For folks who own a Canon full frame system (camera and lenses) it will still make sense to look at the Canon option if they want to augment with an APS-C camera body. It will be larger than the Fujifilm XT-6, but they won't need any (or at least many) new lenses.
One more thing: I'd bet strongly that the XT6 will not be the first 6th generation camera that Fujifilm releases. More likely that the XH3 welcome first, with the XT-6 closely behind it.