I'm sure that for 99.9% of this camera's intended audience / purchasing market....the slightly inferior SNR isn't an issue. The only people who seem to worry about things like this are Sony / Nikon trolls who seem to think it's the only measurement that matters.Introducing a camera that has worse SNR at high ISO compared to a model that was released five years prior is indeed a step back. And this while competitors were making significant improvements in this area year after year. And questionable dynamic range at base ISO while competitors are breaking DR records with each new full frame sensor they release.
Now if Canon chooses to use the exact same 6D mk ii sensor on RP, that would be a "jump" back.
Of course, Canon can still put their marketing muscle behind this product and make it successful with attractive pricing, promotions and product placement throughout the retail channel. Once they have significant market share in the full frame mirror-less market and a respectable arsenal of RF lenses, they can bring out RF mount cameras with better sensors and features and drive the upgrade cycle.
For most users this camera will outperform 99% of it's users.