The Canadian government has made a very slight change to its existing border crossing rules.
Starting in early July, anyone who is already allowed to enter the country can do so without having to quarantine for two weeks after arriving. However, they'll have to be vaccinated against coronavirus and also pass two COVID-19 tests. Americans who haven't been allowed into the country since March 2020 due to the COVID-19 pandemic still won't be able to enter Canada until further notice.