Agree to everything but the tilt screen. We certainly don't need another camera like the R100 with a fixed screen. Fully articulating screens have the advantage that you can use them for selfies, even on a tripod and with an attached flash. Can't do that with a tilt-only screen, besides tilt-screens often have a limited amount they can move up or down.
Design: Make it boxy and small. It'd be fantastic to have a full frame that's maybe even a bit smaller and lighter than the R10. But please leave the EVF and hotshoe, unlike Panasonic.
IBIS: Nice to have when adapting vintage glass, but won't happen. I'm 100% sure the camera is going to slot in between the R8 and the R6 Mark II. With IBIS, it would cannibalize R6II sales.
Memory cards: Don't care if it only has one card slot. This isn't gonna be a camera you bring to a wedding. It's just for casual photography.
Simulation: One thing I would absolutely love to see is analog film simulations. I'm so over those 7 standard Canon picture styles. Canon could work together with VSCO or RNI and offer more refined picture styles that include adding noise, halation, bloom, dust, vignetting etc. I won't happen, but still, maybe someone at Canon reads this.