Media as usual is ahead of the facts here.
I think Cavs view the Nets pick as primary piece in this deal. They know IT's hip isn't fully healed yet, and besides, he's a rental. Sure they want their doctors to examine him, like any other traded player--including Irving. 
I don't think they make this deal if IT was the prime piece. He's a rental and coming off an injury. That's why Ainge sweetened the deal to include the Nets pick.