Bynum wasn't on the team initially, iirc. He was recently asked to join the team and declined.
I really don't think a lot of the players should participate, with the shorten compact season, playoffs until the summer for some it is just too much on the body. This is not a normal year, and I think the players need time to rest after this season.
I think it depends on the player and their own personal goals. Many NBA players have little to no shot at an NBA title in their current situations. Andre Iguodola, Kevin Love, Rudy Gay, Carmelo Anthony, Derron Williams, Chris Paul, etc. aren't going to be winning an NBA title anytime soon, imo. Those players have more incentive to go play as they have a much better chance at a gold medal.
I think the Heat players might bail out if they lose after another long playoff run.