Hunt attendance is better described as an intermittent problem rather than temporary problem. It happens with every major patch release, not just an expansion launch. It's a prolonged problem at the moment because of the increased weekly cap on Revelation and the ability to use nuts to get Cryptlurker augmented. Those not doing Savage will be working quite a while to get all that gear before EW is released.
There are also a lot of new players and many of them are joining the hunt community as they get to level cap. They're going to help keep hunts filled even as players who have been around most of the expansion start dropping out.
Hate to say it but with no word of new servers for NA to thin out population per world, overpopulation may stop being intermittent and turn into a permanent problem.
Reprogramming hunts to be like FATEs in general has already gotten a firm "No". YoshiP said the amount of time it would take to reprogram hunts to act like FATEs is time they'd rather use to create new content.
Can they even program hunts to recognize a player as being cross world and ineligible to participate? Have no idea but I suspect it would still get the same response as the FATE idea. Too much time that would be better spent on other content.
To be honest, how hunts were handled was never in the server's hands in the first place. Any attempt by a faction on a server to enforce its adopted rules on players who didn't want to follow them would be flirting with ToS violations and account bans. I know players who got bans because they harassed other players for killing outside of trains or reset hunt marks after someone pulled earlier than the announced pull time.
SE might have left it up to players to work out how they want to hunt, but they also left it open for everyone to do their own thing if that was what they preferred.
In the long run, players from other servers aren't an enemy. A community doesn't benefit by trying to turn them into one.