I have no idea what the problem with Schildt was...maybe legitimate, maybe not. Schildt was nearly a lifer with the Cardinals...with a 55% win rate...and three for three in qualifying for the post season.
Unless it comes out that reason was for personal misbehavior that meant he had to be dismissed, the GM has put a noose around his own neck. He now has a very old team going for one last hurrah behind two beloved players.
He will now have to go with a manager from outside a stable org, or an in-house candidate with very little experience, following a successful manager. Its not a healthy situation to be in for the guy who wielded the ax.