For the first time since 2017, the Super Bowl broadcast will feature entirely Canadian Super Bowl commercials. This comes from a Supreme Court of Canada ruling in late December of 2019 which aims to protect the rights of Canadian broadcasters and keep advertising dollars in the Canadian market.
The Supreme Court of Canada ruling in December of 2019 was to promote local broadcasting and local creation. The practice is called "simultaneous substitution" and allows for the Canadian broadcaster to air Canadian ads but keep the program the same. When substitution occurs, you see the signal, including the Canadian commercials, on a US channel.
Note: Even though the American commercials may not appear on the broadcast of Super Bowl LV, most of the Super Bowl LV commercials will be uploaded online. Some have already made their way to news feeds and online video platforms days before the big game.