It is very typical of Bruce to find some indirect way of getting the emotional support or connection he needs. I don't think he'd ever be able to ask for absolution or something like that about Jason, but telling Cass about him he can see as the Right Thing To Do. But it's no accident that she's the one he's talking to there, and I agree it's not even just about Cass having, say, less baggage/history with Jason. He does, I think, see some instinctual understanding there.