I think, the Bills are actually sufficient at TE. It is not a position of emphasis in their offense, and the front office seems to feel satisfied with what they have, which is:
Chandler is above average
Moeaki was an "up and comer" if he gets back to where he was, that's a huge bonus
Smith just blocks
Gragg seems to have all kinds of talent, needs to start using it
And I do think Kaufman will be the wild card