Not only are the US the biggest film exporter in the world by far, with Hollywood being a pillar of American soft power, but you can't even apply “tariff” to movies as it is IP, not physical goods (on which tariffs apply). Sure you can imagine schemes to tax these anyway, but that's a huge can of worms to open for the US, are they are net exporters of everything IP related.

The EU has been struggling with base evasion and profit shifting (BEPS) from US companies because it was all about IP and they never dared to tax it in fear of upsetting the US government. But if the move comes from the US first, then they will follow suite with a lot of enthusiasm.