Nonsense. Every player in the league knows they can be traded at any time, and many of them have been.
It's not rocket science. There are 2 huge market, huge $$ teams in the NBA, the Lakers and Knicks. Davis was able to force his freedom at a time (and probably this was a huge motivation for him doing so) when both teams had cap space to add a star to play with him, or in the case of LAL, already had a star on board. Players know they can make more $$ and have more opportunity in those cities. We're always going to come in 2nd to either of those teams for FAs, unless that isn't an issue for the player.
The Celtics are nicely positioned generally speaking. We're a big market team, we're just not LA or NY. We've got a GM with a track record of success, and a head coach players around the league rave about.
IMO, Kyrie isn't much of a bellwether when it comes to this organization, he's a really weird guy. And considering that Jeff Goodman said Celtics players told him Kyrie is difficult to play with and sucks the air out of the locker room, I have doubts whether Ainge's interest in re-signing Kyrie is even genuine.