Let's see the price point of the R5.
In the "Mirrorless" vs "DSLR" battle, the logic I have bought into is that mirrorless is much easier and less expensive to manufacturer due to it being mostly automated. To an extent, we've seen that with the R and RP, but they had no specific DSLR peers.
Now, if the R5 comes out at $3,500, then a similarly spec'd 5DV can come out at $3,500 as well. Canon just makes extra profit on the R5. But if Canon prices the R5 lower, especially much lower, I view it as a bad sign for the 5DV as the larger the difference, the more you can save buying an R5, the smaller the market would be for the 5DV.
While you can argue Canon will just take the profit, but the more I am seeing this market develop, I suspect Canon now WANTs you to go mirrorless so you start buying their uber expensive RF lenses. This won't be about bodies, it will be about getting the market to transition.