I agree with you if he is the one who wants that D, let him doing the work. Like you I used to confront, now I am much more in the wait and see.
Why didn't he tell you about filing since you are still living together? Does he want you to react/get upset so he can validate his decision? What is his agenda for not telling you?
You are doing a great job at detaching and avoiding confrontation, at least the tension is less. Remember for him, you are the cause of his happiness, so his PA was a way to make you react/argue/confront to validate his actions. Also, you need some "peace", it's very difficult to live with somebody who is PA on a daily basis, walking constantly on eggshells drives you nuts, when your mind is on constant fight or flight, it's very tough to think, you become reactive instead of being active.
Now with him having filed, you need to keep your cards hidden from him, do not tell him what your next move is going to be. He didn't tell you about the filing, be very careful when the negotiations will start, have somebody on your side, do not trust him, if he cannot share that info with you, what else did he hide from you? I am not paranoid but sadly I have lived enough to see a few of my friends being blindsided during their divorce.
Ask Jeep for divorce advice, he is full of great ones.
Keep venting here or to a friend, when you vent, you sort out your feelings and it helps to clarify your mind.
Me 52+ WH 57+ Married 20 + Piecing since 2016 (ready to give up...)