In a way, I'm glad that the challenges reset every generation because of the XP boost but ideally I would want to keep the challenges that I've unlocked and new challenges exclusive to specific generations would open up (generation 2 unlocks generation 2 challenges which stay for generation 3 but generation 3 has its own set of challenges, etc.).
Even if those next generation challenges are just extensions of the first generation's. It would also add another benefit to regenerating. Also, for TitanFall 2, it would be nice if regenerating unlocked skins for Titans and Pilots and allowed for cosmetic customization options. That would be a pretty cool wall to unlock that stuff behind.
Regardless, I've almost played 20 hours since launch. This game is extremely addictive, extremely fun, and I dare say it does live up to the hype. At least for me.