>>58045456 (OP)>Piplup This is going to sound like a huge conspiracy theory but for some reason, Game Freak seem very much opposed to giving Sinnoh Pokemon new forms or evolutions beyond the few Megas they already have.
No Sinnoh Pokemon have regional variants, convergent species, or Paradox forms. Even when given the opportunity to make Paradox Mismagius and Magnezone, Game Freak went with Misdreavus and Maneton instead. PLA didn't given any Sinnoh Pokemon outside of Dialga and Palkia new forms or evolutions, and instead gave them to Gen II and V Pokemon, and in ZA, if the leaks are correct Frosslass is the only Sinnoh Pokemon to be getting a Mega Evolution--and this is likely done only because Froslass and Glalie are counterparts in the same way that Gardevoir and Gallade are.
I'm not sure why but Game Freak either hates Sinnoh Pokemon and will never give them new forms or is saving giving Sinnoh Pokekmon new forms for something else.
Personally, my theory is that PLZA will have Sinnoh-related DLC since Sinnoh and Kalos both have evolution/Mega evolution as core themes and because Rowan was Sycamore's mentor