I wouldn’t say I’m “perfectly okay” with it, but I do feel a plan like yours is the “least bad option”. For some of our housing supply, it might just be easier to build high-density on greenfield land rather than upzoning and running into NIMBYs. Paige Saunders has a great video which pretty much agrees with your comment.

The only thing I might change is which GO lines to build along as the Lakeshore lines are already the busiest in the system.