Scott was not within his rights to deceive Madelyne by letting her think she was playing second fiddle to Warren. If he'd blurted out "Jean's alive!"--a natural reaction IMHO--Maddie would have understood what was really going on. I don't know what she would have done, but at least she could have gotten over the worst of her anger before she was ambushed by demons.
Scott walked out and traveled several thousand miles because of Jean. And I very much doubt he was thinking about his marriage one way or another. Indeed, by his own later admission he was obsessed with getting to Jean to the exclusion of all other thoughts.
I don't regard Madelyne's "Don't bother coming back!" as an ultimatum. It as an outburst of anger at a husband who was assuring her they'd "work things out" one moment, then heading out the door the next.
My bad. I was confusing her with the Sisterhood.
Neither did Madelyne know. It was months before she found out about Jean.
I suppose Scott must have told someone his wife was dead before they cremated her. But have you ever seen a death certificate issued for a comic--book--or any other--fictional character? I haven't.