Just in case anyone is wondering how this was possible, the short story: Novo Nordisk did file for a patent in Canada and obtained it. But, by negligence or intentionally, they stopped paying the annual fee in 2018, and did not pay it since. So they lost the patent protection. But nobody could start manufacturing the generic, because they needed to run trials, and that's expensive. But, starting in January this year, they could point to Novo's trial results and say "there, the drug is safe and effective". There was some data exclusivity protection in place that prevented people from doing that even if Novo's patent lapsed.
The conspiracy theory version of how Novo allowed its patent to lapse is that in the absence of a patent, a certain Canadian Patented Medicine Price Review Board did not have jurisdiction to investigate Novo's drugs for being overpriced, so Novo could keep charging its exorbitant prices.