The Bills didn't grade any of the WRs as 1st round. KC disagreed to the point of trading up to get their guy. I suspect all the QBs going so early made their guy available at 28 and they jumped on it.
The ESPN talking heads were puzzled by the Bills move, particularly with KC being the dance partner and both teams needing WR help. But Beane must think he can get 2 WRs in the 2nd that he likes at least as much as Worthy. Many were/are calling KC the big winner of that trade, but that ultimately won't be decided for some time.
I personally didn't like it last night, still not crazy about it. If it wasn't KC, and if the whole Mahomes thing never happened, I might think differently. But ultimately Beane could be right. Only time will tell.