The statistical analysis cited to demonstrate Zay is a 2 is about as deep a dive as jumping into a puddle. It proves nothing. The fact is, much of his production comes when games were not in doubt:
He had 3 catches for 26 yards late at Baltimore. 2 catches for 63 yards versus SD when Buffalo was down 21-3 or worse. He had 1 catch at Minnesota for 17 yards when the score was 27-0. At GB, his 4 catches for 38 yards all came when the score was 19-0 or worse. Against Indy, he had 1 catch for 15 yards with the score 24-0. He had 3 catches for 7 yards versus Chicago with the difference of 28 points or worse. At the Jets, 3 of his catches (for 28 yards) came with Buffalo up more than 2 TDs. And at NE, all 5 of his receptions for 67 yards came with Buffalo out of it.
By my count, that's 22 catches for 261 yards (and 2 TDs) when the game is not in question. There aren't many WR2s who log 45% of their production in garbage time.