The other restaurants tested had 85-90% chicken instead of 50%. The chicken ends up ground up into tiny bits and bound with other things - basically salt and sugar - so I don't think it is possible to have 100% chicken post-processing. The difference is something like the difference between a raw plank and particleboard.
IMO, if it is 85-90% chicken then labeling it "chicken" is not unreasonable.
So long as you're eating chicken, adding in the skin isn't too unreasonable. You eat the skin with chicken wings and fried chicken anyway. And it's not like they're using chicken skins in vegan foods, where you otherwise wouldn't expect the involvement of chicken.
And you can process chicken and still have 100% chicken.