No they won’t.
First of all, companies charge different prices for products/services between different regions all the time. If Tesla made FSD free for the world and charged $15k in the U.S. there’s nothing a US consumer could do except for buy or don’t buy.
They could just lock software by region.
Second point, if EU laws are more “complicated” and you can “forget FSD for years“, how can they offer it at all? So you’re saying laws will prohibit FSD while simultaneously saying people “might” buy something that they by law won’t be able to use? That logic makes zero sense. You can’t have it both ways. The trend for ROW has been nerfed features, I doubt that’s changing anytime soon.
Third, you’re talking about YEARS down the line, no one is trying to solve a potential cost concern for that right now. Breakthroughs and pricing could change drastically during that time.