Yes. Canonical clearly lays out the project motivations, including not choosing to use Wayland, on the Mir wiki page[1].
[1] https://wiki.ubuntu.com/MirSpec#Why_Not_Wayland_.2BAC8_Westo...
[1] https://wiki.ubuntu.com/MirSpec#Why_Not_Wayland_.2BAC8_Westo...
(from other thread on Mir)
edit: forgot the link! http://pastebin.com/KjRm3be1
https://wiki.ubuntu.com/MirSpec