Comment by luckylion

But technically you can also do that with chromium and gecko, but it's a lot of work, so very few do. And those that do don't cut the line, they'll almost all still follow upstream and just apply their changes.

So in the end, they're still dependent on the decisions made in the US. That doesn't need to be a problem, but I don't think "you can get the source code" really changes that.