Can a cheater truly ever change?

This is going to sound dumb because my boyfriend has never actually cheated on me. However he used to be a cheater. Granted we are both almost 30 now. When he was cheating he was 16-22. And he did it a lot. What concerns me is when we did talk about our pasts the reason he stopped cheating isn't even because he realized he was hurting people. It's because of something that happened to HIM because HE cheated. He was texting someone online behind an ex girlfriend's back. Went to meet up with this girl. Got tricked into taking shrooms and everything went down hill from there where he was extremely high and tripping on shrooms and other drugs he was given and then experienced some less than consensual stuff. He started therapy because he realized he was going to end up dead or traumatized AGAIN if he doesn't stop living life so recklessly. Which is good. And I don't doubt what he went through was traumatizing and can make you realize you need to change. But it's kind of sad what got him to "change" wasn't that he hurt people. It's because HE got hurt. I don't think he would cheat on me. He doesn't have social media and is very much a work and go home type of person. He doesn't even hang out with friends much. In the end is it possible for a cheater to change?