>>35195761Trials were a downgrade of the gym system, what are you talking about?
Also, just because they introduced new pokemon mid gen, doesn't mean they weren't always intended for this generation, I remember one credible guy mentioning the Blacephalon was supposed to be in SM so it's pretty obvious that they held back some pokemon so that they had something new to put into the 3rd versions, without the new pokemon, USUM would have very minimal new content.