If these rumors are correct, it causes me to wonder about Canon's strategy... Why go with a single, relatively unambitious body? It isn't especially high resolution, it isn't especially high speed, and it isn't groundbreakingly cheap. Maybe there's something that hasn't appeared in the specs to date - very small? Native EF mount? Unusual image quality in some way? Very high maximum ISO (or very low minimum ISO)?
It doesn't need to be any of them. It's not trying to compete with the D850/A7r3/Z7 for resolution/non-action photography, nor is it trying to compete with the A9/D5/1Dx2 as an action camera. For a general-purpose camera, which this seems to be, the resolution and fps are just about the least important aspects of the body, so long as certain (low) requirements are met. 24-30MP is plenty for this type of body. 10fps is fast enough even for an action/sports body - just not as fast as the latest ones. Even if it had been 24MP/7fps, it would be more than competitive, provided other features were there.
High-ISO performance, dual card slots, AF performance, a solid flash system and a large, fast-clearing buffer will all do much more for the camera than a few extra megapixels or a few extra fps. I doubt it will have a low minimum ISO - this isn't a studio/landscape body and is more likely to be used to shoot candlelit events at night than to make 3m-wide landscape prints demanding the utmost in resolution and dynamic range.
Assuming that the specs we haven't seen contain no surprises:
The Sony A7III is around the same price, but has a full system behind it - unless it's native EF, the Canon won't at first. (it also has very effective IBIS, which the Canon may or may not)
Assuming the Canon AF system is in any way competitive - if it's not, it doesn't even meet the first criterion for consideration - the A7III will be its most significant competitor, although the upcoming A7s3 could provide some pressure from the higher end, if it's boosted to 24MP with top-class low-light and video performance. Why would you go for the Canon instead of the Sony? It really depends on the other features. Certainly, the 28-70/2 and 50/1.2 lenses take a lot of pressure off Canon lens-wise, since they cover a large part of what event photographers need; the Nikon Z6 will have no such luxury at launch, which will likely cost it market share. The 24-105/4 will do a similar job for the casual/travel/entry-level photographers, much as it does for Canon's SLR lineup; Nikon's 24-70/4 will almost certainly be optically better, given it's a less ambitious lens design, but, so long as Canon's 24-105 gives credible performance (and the SLR versions are no slouches) the extra range will likely more than make up for the optical performance for these users.
The thing about lenses is that you don't need a huge lineup, either in your own collection or available for your mount. You need lenses which do the jobs you need them for, and no more. By targeting one or two specific market segments at a time (in this case, it appears to be kit-lens-only and event photographers), Canon can make the camera system ready for users within that segment to jump straight in, with all the required gear available early on, moving to the next segment only after the requirements of the first segment have been met; Nikon could also have done this, but doesn't appear to have done so, going instead for a 'something-for-everyone' approach that doesn't fully meet the needs of any one segment and doesn't seem to provide a compelling reason for any particular user to switch.
Apart from lenses, the thing that would help Canon most is a strong flash system - specifically, full compatibility with Canon's current Speedlite system. Sony's flash system is weak. Unlike with flashes, you don't need new motors or hardware to make a flash work properly on a mirrorless camera as opposed to an SLR - all you need is a compatible mount and suitable software/firmware. Canon already has a decent flash system. It makes sense to use it. This would also tie into a focus on event photography (which the 28-70 and moderate body specs would indicate), since such photographers tend to be heavy users of on-camera and portable off-camera flash.
Older editions of the A7 series are either much cheaper (A7, A7II) or around the same price, but with a much higher resolution sensor with class-leading image quality (A7rII) - possibly at the cost of some video quality and features (we don't know exactly what the Canon has). They also tie in to the full Sony system.
Canon is targeting one or two market segments strongly here, not hit every segment with a body that works out to being average at everything. No doubt they'll release a high-resolution body at some stage - that may be why we haven't seen a 5Ds2 yet. But that's not the market segment which this body is trying to target.
The Nikon Z6 is about the same price and resolution, significantly faster (unless the Canon's 10 FPS spec is wrong), and has high-grade weather sealing (Sonys don't - we don't know about the Canon).
It also doesn't have a 24-105/4 (or 24-120/4, since that's Nikon's kit lens) for the kit-lens-only photographer, nor does it have anything particularly compelling for the event/wedding photographer. If you were shooting fast action or after ultra-high resolution, you wouldn't be looking at either body anyway.
As for the frame rate, these cameras aren't targeted at wildlife/fast action anyway, and long lenses won't be available for a while (at least as per Nikon's roadmap). Even if they were, and suitable lenses were available, have you ever been in a situation where 10fps wasn't fast enough but 12fps was? No-one ever complained that Nikon's D5 could only make 12fps, while Canon's 1Dx2 could make 16fps. The 1D3 shot at 10fps and the D3 shot at 9fps, so 10fps is more than fast enough for most action.
