While it is very nice that cascading alliances have been fixed, there is a new problem that has been introduced that can lead to an aggressor facing far more enemies then they bargained for. Now it is possible (and in fact likely) for defensive nations to gain new allies as the war goes on and to call them into their wars years after they started. This wouldn't be a problem, if it wasn't also impossible to gain new allies as the attacker.
Consider the situation where one nation is trying to gain independence against their overlord. That nation can potentially gain allies before the war through the support independence relationship, though this is much more difficult to gain then regular alliances. However, once they do start the war for independence, they are considered to be the attacker and cannot form any other alliances after that. The old overlord can gain new allies, and an independent seeking nation might find themselves facing several large powers they hadn't anticipated fighting when they started the war. There is no way to prepare for this, or anticipate it. There is no way to deal with it once it happens either. You just lose.
Consider the situation where one nation is trying to gain independence against their overlord. That nation can potentially gain allies before the war through the support independence relationship, though this is much more difficult to gain then regular alliances. However, once they do start the war for independence, they are considered to be the attacker and cannot form any other alliances after that. The old overlord can gain new allies, and an independent seeking nation might find themselves facing several large powers they hadn't anticipated fighting when they started the war. There is no way to prepare for this, or anticipate it. There is no way to deal with it once it happens either. You just lose.