As a disclaimer - I was a WW in my first marriage 17+ years ago, currently a BW in my 2nd marriage.
As a WW I remember suddenly having zero control of anything, and as a grown adult that really pissed me off. All of a sudden I was treated like a troubled teenage child by me XBH. Where was I going, who was I talking to, how long will you be gone, let me see your phone, give me your passwords, ect.
Holding onto things like AP's name, phone number, and some details from the A was the only thing I could control, so I did.
XBH and I didn't ever really get into R, though we did go to a few counseling sessions. I was still very much in the fog and defensive. All of a sudden, everything wrong with the marriage was ALL my fault now. That he was the perfect little BH and I was the wicked witch of the west. I didn't understand that before we could get into the WHOLE marital issues, we had to deal with this pain I caused, which was really all my fault.
Even though I regretted my ONS immediately and knew that it was the absolute wrong thing to do, it took me A LONG time, many many individual counseling sessions, many books, and a lot of healing to finally realized how stupid, immature, and childish I had acted and thought. That even though I had valid feelings about how our marriage was, it never ever justified what I had done.
My question though to you Cedarwoods is, have you asked your WS why he finally blocked and deleted everything?
If you ask him and he says - Because you asked me to, that's a placation response. He either needs to do deeper healing or he's only doing this to get you off his case.
If you ask him and he says - Because it was the right thing to do, that holding on to those things was harmful to not only you but to himself. That is a deeper healing response. This kind of thinking tends to mean that he's creating new thought processes, changing his character and morals beyond just placating you.