This article is garbage from a rumor stabdpoint and that's a good thing.
It's not really a rumor. It's just pointing out that the Celtics have 18 players, counting Evan Turner, and need to be at 15 by the start of the season, so if there is no trade, it seems almost certain that Bogans, Johnson, and Babb are going to be waived before the first game.
As much as I like Phil Pressey, if I were Danny Ainge, I'd have to think hard on whether letting go of Bogans' 5.3M of tradable salary cash relief was less painful than just eating Phil's 816K salary.
Bogan's salary does not become vested until January 7th. There are likely going to be real opportunities to make trades between now and then where having that contract could be very valuable. It would be a shame to just 'cut' him now.