When asked after the BAFTA ceremony if Ang Lee was the Godfather of Matilda, because Ang called himslef "matchmaker", Heath and Michelle said that it's Jake actually. Later during a press conference Jake confirmed he was the Godfather. Ever since press mentioned the fact every now and then.
It seemed that Jake and Heath were very close during BBM promotion, but we really can not know for sure how close they remained (you don't have to be close to your kid's Godparents btw). The one lived in L.A. the other in N.Y. I believe they saw each other every now and then, but that's about it. Each had their own life.
I'm sure Jake, when he heard about Heath's death was very sad, but i doubt he was as devastated as some claimed. He even went to a Rufus Wainwright concert days after Heath's death, or shopping in Soho with Reese over a month ago etc. Life has to go on and his main priority at the moment seems to be his girlfriend. I also didn't expect him to react like Jack Twist would have reacted if Ennis Del Mar had died before him. I can distinguish reality from fiction and while i understand that life goes on and he has other priorities in his real life, a statement/tribute would have been a sign of respect towards Heath, I personally appreciated all the tributes from Heath's family members, friends and colleagues. Jake for whatever reason, may it be personal or professional, decided not to do it and i don't think we will get anything from him. If we want it or not, we must accept it and move on.