Is it possible for a man to not miss his ex gf and regret leaving until 6 months later while in a rebound relationship?

He reached out to me saying he had a fight with his gf and is done with her and then the next day told me they worked it out. I’m confused as to why he reached out to me about it at all? Does it mean he’s thinking about me?We were together for 10 years with a child. He moved 5 hrs away for a new job, we got into a fight and broke up and 2 weeks later he had a new gf. I think we both have unresolved feelings because it all went down super fast but I haven’t been able to start a new relationship yet and he did right away. He’s also a sex addict so I think that’s why.