The only real space in that list for fillers to be found is the food starch, but it's less abundant than water, so if there were a bunch of fillers, it'd be pretty soupy. (Its typical use is as a binder, and it'd make sense for it to serve that purpose in a nugget - you're not going to manage to make a white-meat nugget without some.)
There is certainly a texture difference between a whole-chunk nugget and one made from pureed meat, but you'd see the same sort of texture difference if you ground up a filet steak, too.
> White boneless chicken, water, food starch-modified, salt, seasoning [autolyzed yeast extract, salt, wheat starch, natural flavoring (botanical source), safflower oil,dextrose, citric acid], sodium phosphates, natural flavor (botanical source).
The only real space in that list for fillers to be found is the food starch, but it's less abundant than water, so if there were a bunch of fillers, it'd be pretty soupy. (Its typical use is as a binder, and it'd make sense for it to serve that purpose in a nugget - you're not going to manage to make a white-meat nugget without some.)
There is certainly a texture difference between a whole-chunk nugget and one made from pureed meat, but you'd see the same sort of texture difference if you ground up a filet steak, too.