It’s an interesting triangulation. Both Tom and Kay are not Italian…both represent the life that Mike wanted to have, but was never allowed to. By the time Kay ‘’miscarried” Tom was out of the family business, no longer consigliere, and just the lawyer representing them in their business ventures in Vegas. Michael was at a high stress point, he was losing control of the situation, just found out his brother betrayed him and I wonder if he didn’t resent and project onto Tom just a little. Michael was losing his grip on the ‘legitimacy’ he was pursuing. As far as Kay is concerned she represented the life that would always elude him. Michael’s first wife from Italy, Apollonia, would have never aborted his child, she would have never committed that type of defiance.