Amendola isn't just a backup for Edelman, he had almost 40% of their combined snaps. If either one of this guys goes down, the other can't just suddenly increase their snap count to compensate. Someone else has to be there to slot into place.
To the extent that he can sub in a portion of Lafell's routes (slants), possibly take 2nd TE routed if one of them goes down, or possessions that might go to the Vareen replacement, he could be considered a utility infielder.
I'm not saying he can fully replace any one of them, but he might be able to competently sub in for one or another.