You ain't heard nuthin! I lived in the greater NY area for years. Non stop talk, with the strongest opinions of people who are certain they are right!
You are right though if the KC line can't keep the Broncos pass rush off Mahomes, it will be a long day for him. Hence a 13-9 KC win is possible.
As to Mac Jones, he hasn't played well enough in the last two weeks to supplant Purdy. He's filled in admirably, redeemed himself (though not to the level of Darnold, I don't think), but Purdy will play as soon as he's truly ready.
No one surprised Fox fired Sanchez. I'm only mildly surprised the are putting Brees in the booth, when they had Brady Quinn the last two weeks, and he did well, and has done quite a few NFL games in the past (though mostly an NCAA guy). Curious to hear how Brees does.
If I were Seattle I'd be a bit concerned about Arizona as well. They have been at least good all season, and they seem to have really rallied behind Brissett. Now that he's been given the keys to the car, they are going to be a tough out for anyone, including Seattle.