I think the biggest (practical) changes we would see are weights and stiffness. Perhaps different materials. Carbon fiber? Discs with metal inserts molded into the rim? Things along those lines. Rims will get huge, putters will get heavy!
Rims will get huge as in we will see speed 16, 17, 18..... discs or are you thinking along the lines of what salient did and made a large diameter distance driver. For both, I dont think they would actually be utilized. Salients disc flopped in that it didnt actually go further like they claimed and the Gateway Ninja (not PDGA approved) also didnt really show more distance or accuracy gains.