#2 Expansion
It’s certainly possible that, not unlike The Shield, WWE would let the core members of The Undisputed Era stay together and function on their own as a successful faction.
However, they’re a group that already grew from three to four members while they were in NXT, and they certainly could continue their expansion to give other talents the rub, besides shoring up their ranks against anyone getting injured and disrupting the crew’s momentum.
Alternatively, they could absorb a veteran talent or two to give the group more immediate credibility with main roster fans who don’t follow NXT.
Expansion of a successful group is always a tricky proposition. In extreme cases like the New World Order, it badly watered down the core members who were over.
Additionally, there’s the risk of losing storyline focus. WWE seems to know what it has in this group, though, and if they were to expand, we can guess that it would happen with care.