#2 The Shield reunion being a one time deal
The Shield getting back together is a big deal, but it also might only turn out to be a one time deal this time around. Of course, a lot of the WWE Universe probably doesn't want to hear that, especially with how iconic the group has become, but there isn't much justification or point to The Shield being together long term.
In fact, between Dean Ambrose's status still being up in the air, Rollins seemingly set to become Universal champion and Roman Reigns still needing something to do, The Shield can't last very long before showing cracks. Beyond that, WWE can't keep the Shield going very long before it starts to lose its appeal and that's yet another reason this needs to be a one-off.
Again, some fans are going to be upset about this likely being a one-off, but its the only way the company can make The Shield reunion work without it overstaying its welcome. In all honesty, its a tool WWE has used one too many times and while it is cool to see these three men share a ring together, WWE can't keep relying on it.
Vince Russo answers who killed WCW HERE