Rivers, Newton, Wilson, Brees, Tannehill, Tyrod Taylor, Big Ben, Brady, and Carr are the only QBs I've noticed that actually have their unique motions work. Every other QB I've played with so far uses this same "generic" motion in game.
I first noticed this 2 years ago. I brought it up here + Twitter and actually talked to some of the devs about it. I got told it would be addressed in the next game, and here we are :/. What's much different this year is what I captured in the video. I think I counted, like 4-5 throwing styles that were unique. Every other one (and there's a gazillion of them) are the "generic" motion. It was not like that the last 2 games. In the last two Madden games they would be unique motions assigned to each player, viewable in the "styles" customization screen, but just wouldn't work in-game. Now it's just the generic motion they've been using since Madden 06 across the board. Interestingly enough, Eli Manning has a unique style applied (I think it's Slinger 8 off the top of my head) that has worked in the last two games but not this year, despite being one of the few styles that are viewable in the customization menu.
I love the little details in Madden and was so pumped when they added signature throwing styles back in 09. It's disheartening to have brought this up 2 times in the past, been told that they were aware of it and it will be fixed next year, only for it to have happened a 3rd time. I think this actually happened back in Madden 15 or 25 at launch and it was patched up in a week....I'm hoping they'll actually fix this as it's something I really enjoy in the franchise.