Wanda's not here anymore for that.
Still, maybe he saw something. After all, with the destruction of the capital, Jetstone's treasury will be taking a immense hit. Maybe Cubbins saw that his upkeep would be too much with better casters around.
And yeah, still pretty sure capital is done for. After all, tower is crashing and unless there's a massive change of side from the decrypted soldiers, Decrypts units still have the advantage over the remaining Jetstone soldiers.