Wayland being a requirement sounds like a sound choice in terms of maintenance and the issues of X itself. Applications don't need to update to GTK5.
What are these issues of X?
Because everyone talks about the issues of X, but Gnome, KDE, Xfce and others run flawless on X, but these same desktops have problems when running on Wayland.
X has some fundamental security issues:
https://security.stackexchange.com/questions/4641/why-are-pe...
The lack of problems on X and the problems on Wayland are mostly an issue of maturity.
Others are doing the same, probably to take some control for themselves, but have a look on the recent conversation about GTK5 being Wayland-only.
It is the same playbook they used to force Systemd adoption all over again.
So, yes, they are still using the same playbook.