(why would PHX want to do that?)
They don't have any intention of signing him and want to save some money (if they're above the salary floor) or doing the player/agent a solid to build goodwill.
If they’re above the salary floor, it’s only by a few hundred thousand dollars, so there isn’t much to be saved there. As long as Monroe is getting minutes, he won’t lobby too much for a buyout, because he’s getting his chance to show for his next contract. Phoenix might buy him out after the trade deadline if they’re unable to get a second-rounder for him and they want to give minutes to someone younger, but I wouldn’t expect it before then. I know people have mentioned December 6th, because they need a roster space for another move at that point, but I don’t see Monroe being the player cleared.