Would you buy it?
How many do you know who would ACTUALLY buy it?
I mean, I know that I would. Of course they're not going to base their market strategy based on what I want, but I can't imagine I'm alone.
To me, the most interesting part of Canons statements quoted here is the part about balance:
For example, if we have higher resolution, then we know that that will skew the balance, and the sensitivity will be lower. That is a physical mechanism. So, in a flagship, we would never focus on just one aspect of the performance that would destroy the balance.
Increasing sensor resolution would (according to them) "destroy" the balance of speed, quality, performance and reliability.
While I can understand that, I would argue that the current R1 isn't a very "balanced" camera to begin with. It is very, VERY heavily leaning towards specifically high-speed sports shooting. The (AI) autofocus, readout speeds, burst rates, responsiveness, noise performance and image resolution, everything there screams "high-speed sports photography". In fact, they even sacrificed some ISO performance for increased readout speed over the R3!
There are many professional applications, including wildlife, landscape and portrait photography, where a higher resolution sensor would be preferable at the cost of some noise performance and maximum burst rate. I know that I'd be happier with a 45-50MPx R1 with 30fps burst rate than the current R1 doing 40fps.
Is it a dealbreaker? Absolutely not. 24MPx is enough for most applications, and I own the R1 and I definitely enjoy it. But I would have preferred the balance of the specs mentioned by Canon to be more... well, balanced, rather than being pretty much exclusively aimed at sports photography.
The R5 is a nice high res body, but to me the resilience, battery life and better viewfinder of the larger body are more important.