Well, the main reason why Wayland even exists is, that the X11 maintainers got fed up with a design from a time when graphics cards were not even a thing yet and decades of patchwork. They wanted to move on to something that has way less technical debt. Sure, X11 won't go away anytime soon, but finding people who actually want to work and maintain that codebase will be more than a little difficult.
No, they mention that they work closely with the OpenBSD team, which maintains an explicit fork ("xenocara") that maintains the NetBSD ABI. It was OpenBSD that added wsdiplay and wsinput, which are frankly better in a lot of use cases than Wayland.
