I think most people who even know the difference between x11 and Wayland are much more privacy conscious then those who don’t. 0% of people going out of their way to jump through all the hoops to get plasma working on x11 would ever opt in to such metrics.
Nah, don't think so. When I setup my main dev desktop (a Debian variant) a few months ago it defaulted to X11 and getting Wayland to work on it was a pain in the butt.
That being said, on a different box with an older gen Nvidia card (3070) it defaulted to Wayland and just worked out of the box.