Yeah I think a lot of people are missing that this is a leaked early development announcement rendering picture, I doubt Canon would change the grip material much unless they found a way to make it even more gripper or better for the user. I'm sure in person this camera will look just amazing.
I think bbasiaga is on the money here. Canon probably had to reevaluate how they would handle the 1Dx Mark III existing with the R3 at the same time.
I also think Canon can tell that the market is moving towards high-res, high-speed, and probably wanted to make a camera line for the professionals who wouldn't normally be buying a mirrorless camera. I do think that means that the R3 will not be a hugely high-res blockbuster, but instead a tried and true camera built for speed. The most important thing for 1d users is reliability, so that might be the focus here.
I would guess that if and when the R1 comes out, the R1 would be a camera that totally breaks the mold in ways that current pros might be hesitant to jump into at first. That said, no one said the R3 can't be 45 megapixels. I expect 24 mp, but if 8k is just where we're at right now, 45 mp might soon be "normal" resolution, and then the R1 could be upwards of 80mp.
I hate to compare lineups, but I'd say the R3 name makes sense as an A9 competitor, and the eventual R1 could be more of a A1 competitor. I could be wrong, but I think Canon is very aware of the importance of the 1 series name.