From what I read about this it was basically an attempt to stop Hollywood production from going overseas. Foreign movies performing in the US box office only account for something like 3%. A 100% tariff on foreign movies essential means they make no money in the US. MAGA could care less.
Canada will be affected by this. All crappy Korean TV series that are made in Korea for netflix will be taxed. The world will now impose tariffs on US movies, including those on netflix.