I think Mira may have to prove to Skate Canada that she is ready to compete before going to Skate America. I know if she was a US skater and had bombed that badly at Worlds, USFS would insist on a competition, close monitoring or both.
ETA: Actually, if a US skater had that bad a finish, I'm not sure his/her name would be submitted for GP assignments.
But USA has the luxury of having a long list of ladies with high enough rankings to get GP assignments so yanking an assignment from one would likely give another an opportunitry. Canada does not have that luxury. Yanking Mira would not open up spaces for Canadians.
Mira is closely monitored though. All national team members have to show up at a monitoring session ( where the public has access to some of it) before the season begins.

There is a small but, shall we say, rather vocal group of Internet posters who are just not happy unless there is an active Mira-bashing thread going on somewhere. 