I always thought McNair saying that he wasn't making Fox and Haliburton available in trades and planned to build around them was pure posturing. It sounds a lot like he just didn't get the offers he expected and/or had his offers rejected.
When a team is this bad everyone should be available unless you've got a rookie on the level of a Kevin Durant (the Sonics went 20-62 his first year but there was enough visual & statistical evidence that he was going to be a star)
That said, kind of a weird thing to say that losses this week by a combined 70 points WHEN FOX WASN'T EVEN PLAYING is a reason to think he's on the trade block. If anything it says the opposite. "Sure, the Kings are terrible, but they are historically awful without De'Aaron". I don't necessarily believe that, but it makes more sense than what that article is trying to say.