Board Thread:General Discussion/@comment-26475399-20150621155411/@comment-26091912-20151021082038

^ Aizen may have a contingency plan for every situation, but nobody is that provident.

In order for this to be true, Aizen would have to account for: the Wandenreich's existence prior to being imprisoned, Royal Guard arriving, Ichigo going to the Royal Realm, Ichigo breaking the Royal Realm barriers, Yhwach invading the Royal Realm, Yhwach killing the Soul King, Shunsui releasing him, and others factors and variables which would require impossibly accurate foresight, that no one, not even Yhwach, can possess.

Even supposing he really did plan all this; it doesn't account for the fact that he must defeat (a now absurdly powerful) Yhwach. Aizen is only joining the fight against Yhwach, because his existence is at stake; just like everyone else's.