Avoidants sharing more post-breakup?

My fearful-avoidant ex and I recently broke up, but still have to interact do to an unforeseen pregnancy. His behavior since finding this out has been a complete 180: he's more empathetic, apologized for the first time in our knowing of one another, and has finally shared many of his fears/underlying emotions/past that he believes contributed to him not being "the best version of himself with me." This has been incredibly confusing to me, and even though I know that our dynamic is toxic (I lean towards preoccupied), hearing him tell me that he's going to be there for me and seeing him show up and appear to commit to personal growth and responsibility has been difficult. He has, of course, specified that he can only truly be there for me over issues r/t to the pregnancy, but separating the reality of that from the feelings I have around our breakup has been trying. I've been extremely resentful about him not showing up in this way while we were a couple, and have expressed this to him in angry outbursts, which isn't something I did when we were together. I know it falls on me to stop that... it's hard to process my feelings of anger and wonder why this couldn't have happened while we were together, esp since he often told me he never wanted to lose our core connection and was working hard to heal our dynamic through personal therapy, etc. I should also say that during our relationship, he said he really wanted to go to a couple's counselor, and had a name for one, but never scheduled an appointment (he said he would, so I left this up to him). It wasn't until I found out I was pregnant, however, that he immediately scheduled therapy for us so we could engage safely over matters r/t to that. We have had two sessions thus far, and I very much want to get past this so I can make the pregnancy the most important focus of ours.

My question is whether or not any of you have dealt with an FA or DA who, upon breaking up, suddenly becomes more open, caring, and shares more information about their feelings. Intellectually, this makes sense to me given that there's no more pressure of intimacy or closeness, but on a feeling level, I just don't get it. I know I'm not totally blameless in this, and that avoidants come with their own set of fears around closeness that are just as valid as mine. He's certainly not a bad person, and I feel so guilty for being pissed about what I *perceive* as intentional mistreatment and manipulation. Any insight would be greatly appreciated! I'm hoping it will help me process and get to a healthier place since we both have to make the pregnancy a priority.