Maybe I'm just speaking for myself, but it seems to me no one can predict the outcome of this game. (I mean, to the extent that we can predict more or less accurately.) The outcome will seem obvious only in retrospect either way it goes. "Of course the Bills won. They always win the regular-season matchups." "Of course KC won; the refs rigged the game!" "Of course the Bills won; KC was overdue for a loss." "Of course KC won. How could Allen overcome losing three starters on offense?" And so on. Tell someone who hadn't watched the game either outcome and they'd nod knowingly.
My take is that the Bills at full strength (including Milano) are flatly better than KC this year, better enough to win in Arrowhead in January. But not having Coleman, Kincaid, Brown, and Milano, offset only by KC missing Pacheco and the kicker? Edge to KC. But it's in Buffalo, so more or less a tossup.
Hate to say it, but it'll come down to the refs. If they call a fair game, it really about as 50-50 as a game could be. (A BIG if!)