I think what he was saying is that for him to consider trading Lafreniere, he would need another team to seriously overpay. So he would be part of a package for an elite player, like Matthews or MacKinnon. I think it's pretty obvious he wasn't saying that he would take Lafreniere over Matthews or MacKinnon.
He is saying he wouldn't trade him to upgrade one spot at our deepest position other than LW (defense). Frankly, neither would I, nor any other Ranger fans. The Rangers would be stupid to trade Laf, even if they are in "win-now mode" (they are in a hybrid state, but whatever). They are better off letting him "bust" until he's 23-24 than trading him for a guy like Chychrun, who is a good player, but doesn't really move the needle that much with our defensive depth.
For one, he would arguably not even be on the PP - he'd be in competition with Trouba and Miller for PP2 minutes (20-30 seconds) and maybe he would win that, but Miller is developing into a Hedman-like player. Eventually he will take that role. He is also a completely different player than Lindgren. Fox needs a bigger, stronger D partner with defensive acumen, not another guy who is an offensive minded defenseman. I don't really think Fox would fit well with Chychrun, honestly.
If the Coyotes can get Lafreniere or another similar player for Chychrun, I would be shocked. I could see them getting a 1st and a good prospect, plus maybe a minor roster player or another pick, largely because his contract would be viewed as a value deal and the Coyotes can even retain, but it shouldn't be from the Rangers.