The Bills weren't going to keep the run of never losing by more than one score going forever. Better it happened now at the beginning of the season so they can evaluate and move forward.
KC got blown out by two teams last year, one of them the terrible Broncos. Good teams lose games. Good teams lose by multiple scores sometimes. The Bills have been a huge outlier with their close losses.
I don't like it because those are still low percentage plays. And you can say Coleman should have made the catch, and maybe that is true, but the defender was still all over him.