Is there an actual reason or source for why people are expecting the new game to have a different model?

Don't get me wrong I'd love a new model (and a laundry list of other visual tweaks ((feel like I'm the only one bothered by how small and short the models are in Frontiers, if you stand by some shrubs Sonic is barely taller than them if not hidden)), but I've seen lots of buzz about this but not sure if there's some rumor or leak I missed.