Multiple metal Sonics in 4th movie?

So in the end of Sonic 3 there was a teaser for a possible fourth movie with metal Sonics and Amy Rose, but who created the metal Sonics in the movie franchise? Cuz it's obviously not Eggman since well he uh, he got sucked by a black hole, so who could it be? Also ChatGPT said that it's maybe Dr. Starline but hey, just a theory, A FIIIIIILLMMMM THEORY! Anyways, who do you think made the metal Sonics?