A lot of teams using their athletic, receiving TE's in the slot or the outside in certain packages or plays. It creates mismatches. But until the TEAM decides he's a listed WR, he is still a TE.He's used as a wide receiver so much so Richard Sherman had to play man to man coverage on him during this past season.
For instance, Mathias Kiwanuka has a body of a DE, but the Giants for several years used him as a LB. He was officially listed as a LB so it made sense for people to call him by that position. Sure he moved at DE on dime or NASCAR packages, but he was still listed as a LB on the team's depth chart.