I don’t think changes to student visas has anything to do with it. It’s still early for Canadian admissions.
Canadian universities never used to give out admission offers until May since decisions are primarily made based on grade 12 marks. Then a few years ago some non-competitive programs started doing US style early admissions, typically in Feb-March time frame, supplementing with grade 11 marks where needed. Then more universities jumped on board and started doing the same. Then some started sending out even earlier offers in Dec-Jan. It’s become like an early admissions arms race and more and more students are getting admitted in earlier rounds, but generally not to the most selective programs. This year in particular I’ve been amazed at the number of students who’ve already gotten offers, it’s more than has ever happened in the past.
Even still the vast majority will still be waiting until May.