Push the roo back to whenever you want, it's yer fantasy.
The Canadian maple leaf roundel was actually approved in
1924 but not used on aircraft until 1946, although it was
used on the ensign from 1941. Also an entry in the August
1941
Air Trails CAVU 'aviation gossip column' about
a visit earlier that year to the Little Norway training facility
and Malton makes note that the RCAF roundel at the base
entrance had been changed from red-dot to maple leaf
center.
So perhaps in another timeline the Canucks went ahead and
started using the maple leaf roundel in 1941 and once the
Oz and NZ pilots saw it they started agitating for their own
identity and the roo and Kiwi appeared sooner.