you appear to have jumped to step 2 in the masterplan, and completely skipped step 1. It's not even mandatory yet, but when it is, the choice will be between N<10 providers, most of them almost certainly American companies
For Mozilla, I'm not sure, but they often follow Google's lead, and there is a strong case for Google to go that route
In any case if it ever starts defaulting to on in any browser, it's very likely the others will follow suit, as it's easy to imagine quite a lot of PR around the security benefits of the brave new world