His quills in both Lost World and Forces are shorter than Generations and Unleashed, and Sonic is posed the same way as his idle animation in Forces.
...NGL, I didn't notice until someone pointed it out.
The biggest pushers of the argument have been people like Chaomix and Procrastination Sam. They're big Sonic content creators, so their opinions on the model (which are negative) have been spreading around.
I do not at all encourage badmouthing someone over an opinion, especially over something completely trivial such as this, so the side defending the model in a hostile manner ain't in the right either. TBH the whole thing is a mess and peeps need to get a grip.
...Although I do admit, if the one screenshot I saw of Chaomix comparing the Forces model to OG movie Sonic is something he actually posted, then that is pretty yikes.