❗SONIC 3 POST CREDITS SCENE SPOILERS WARNING❗
So, i was rewatching the post credits scene in Sonic 3, when i realized that when we first see Metal Sonic, his eyes look more thin, and is just a red oval.
But when Sonic says "But you got a few details wrong." or basically when he gets to have a proper look at Sonic, he adjusts his eyes to look more like Sonic's eyes, which looks more thick, if you understand what i mean, because i can put only one image in this post. I noticed that if he is copying Sonic here, there could be a chance he would copy more things about him, like his movement, body language, etc. And that includes VOICES. I think you know where i am going with this. You see, in Sonic Heroes, when Team Sonic finds out Eggman was a fake, after they run off, Neo Metal Sonic comes out and says "All life form data, successfully copied.", which could mean that if they go more into Metal Sonic in the movie, Neo Metal Sonic has a chance to appear. This is where the theory comes in, in which i made a chart for:
Basically the chart is what i mean by this. These are the possibilities, and hopefully atleast one of them applies to Sonic The Hedgehog 4.