I believe this is likely true but I find the headline unremarkable. It would be malpractice if the Celtics didn't call the Sixers to probe about Simmons. You have to have the conversation.
I also believe today's headline is probably because Simmons's agent or the Sixers want to create the impression around the league that there's demand for the player. The recent headlines around his lack of cooperation with the Sixers and his mysterious mental health status haven't been good. Today's story plants the seed in the minds of people around the league that Simmons still has value, at about the level of Jaylen Brown. I'm not saying I agree, but I think that's the message that was intended.