If Terrance Williams is a body catcher, then so is Will Fuller. I'm a Notre Dame fan - I have no axe to grind on this. I call it as I have seen it - Fuller is not a natural hands catcher the way a Cris Carter, Randy Moss or Jerry Rice were. He lets the ball get into his body more often than not.
And I have argued about the body catcher label for Terrance Williams too. I have a very very hard time believing a "body catcher" could make it to the NFL, let alone become a starter.
If Chris Carter, Randy Moss and Jerry Rice are the standard for guys who haven't played a single down in the NFL yet, than everyone will look like a failure.
In his 2014 highlight video, he shows just as much ability and propensity to snatch the ball out of the air as let it get to his body (I am posting highlights, but I have watched every game for two decades).
Many of his "body catches" are either on deep balls over the shoulder, where many coaches actually tell you to cradle the ball, or on catches where he is expecting contact and "gets small". The guy definitely lets the ball get to his body some times, but I don't think it's a trait. I think it's something you could easily coach out of the kid, given how aggressive he's also shown he can be, snatching the ball with his hands. His endzone grabs in particular, show his ability to snatch the ball out of the air.
Here is his 2015 video. He has more cradle catches in this video, but also deals with a lot more underthrown balls.
I just think it's clear from the tape, the guy can and will catch with his hands when he needs to be aggressive. He does drop too many passes, but the huge plays he makes taking the top off the defense make up for it. I don't know anyone here who wouldn't take Beckham or Desean in his prime and both of those guys drop a lot of balls--they come back with huge plays though.
There may be a handful of guys in the league I would say are pure receivers, meaning they always go aggressively for the ball. Those would be Fitzgerald, Beckham to an extent, Dez (when he is on and healthy) and AJ Green. Even Julio Jones and Megatron will let a lot of balls get to his body. They're just so big it doesn't matter.