should hubby call back his estranged son because now he and wife are expecting a baby?

hubby and i have been married 9 yrs(second marriage for both of us)...at the time of our wedding his son would have nothing to do with us, with being coached by his mom...(hubbys divorce was nasty)...and no I had nothing to do with their marriage breaking up...his son and hubby has not spoken for all these yrs,until he was married..we were invited..and treated very coldly..since then he has called to tell his dad they are having a baby..this conv ersation was strained..he had to do all the talking and alot of coldness coming from the son..so now my hubby does not want anymore contact..i think hes wrong..and should try to fix things for the babys sake..what should i do? give up or standup for what i think is right?