I don't think contacting Cass is actually that simple. We see Bruce going through people he could call and talk to after Babs calls, we see him face his mortality in the mirror, prior to the story we saw him project Jason's fate to girl who OD'd. Bruce needs to tell someone to talk to, but at the same time he isn't someone who just goes to talk to people about his feelings.
So I don't think it's fair to say he contacted Cass for her sake, I think it's for both their sakes. He needs Cass to understand why he did what he did and why he is behaving the way he does, to comfort her, yes, but he also needs to talk to someone who understands what a normal life means to people like them. That speech he gives to Cass is filled with regret and is quite rare in revealing how Bruce wonders about his own actions. It isn't just about Cass, it is also about Bruce, and the scene in the scans, to me at least, indicates very strongly that Bruce also realizes that.