In July we got a teaser for Mega Evolutions and prior to and after the teaser we saw a number of events for Pokemon with Mega evolutions. June Community Day was Weedle, Pinsir had a raid day, August Community Day was Magikarp, Latios and Latias had a raid weekend, and July Community Day was Gastly. We also had Abra Community Day in April.
My guess is September Community Day will also be a Pokemon with a Mega evolution. So which Pokemon are left?
Excluding Pokemon who have already had a Community Day (even though Niantic has made repeats available, looking at you Aura Sphere Blastoise) and regional Pokemon there aren’t many.
Aerodactyl is unlikely as it is a one stage Pokemon and has been available in raids and Research tasks for a while.
Scizor - Obviously the 3 stage Pokemon requirement is no longer a requirement for Community Day. But I don’t expect to see one for Scyther as it was recently featured in the Bug Out event.
Houndoom - Although the shiny is already released we could see a Houndour Community Day. I would expect a Fire type move. Overheat or Niantic could add Inferno to Pokemon GO.
Mawile - Unlikely as it is a one stage Pokemon.
Aggron - My best guess for September Community Day. It is a 3 stage evolution. The shiny is already available but clearly that “requirement” has gone away recently. Aggron becomes a pure Steel type when it Mega evolves so I would suspect Iron Head or Flash Cannon.
Medicham - Unlikely as it was just available during GO Fest.
Banette - A potential candidate but more likely for October to coincide with the Halloween event.
Manectric - A potential candidate but it’s already got a decent moveset and it’s not really great at PvE or PvP.
Absol - Unlikely as it’s a one stage Pokemon
Garchomp - While we would all love a Gible Community Day we just had GO Fest and Dragon Week.
Lucario - A potential candidate despite being a 2 stage Pokemon. However it’s already got a great moveset.
Abomasnow - Unlikely as it recently received a moveset update and performs quite well in PvP as a result.
Pidgeot - Laugh now but honestly would you be mad at a Pidgey CD featuring Sky Attack!?
Slowbro - Unlikely as I suspect we’ll see an event for the release of Galarian Slowpoke
Steelix - A potential candidate and Earth Power or Bulldoze would be welcome additions to the movepool.
Sableye - A potential candidate but I suspect we’ll see spawns during the Halloween event. It also has a spotlight hour tomorrow.
Sharpedo - Unlikely.
Camerupt - Unlikely.
Altaria - A potential candidate given we just had Magikarp Community Day. Plus Altaria is another Pokemon whose Mega evolution changes it’s typing. Mega Altaria is the only Dragon/Fairy type Pokemon. Moonblast is a likely move.
Glalie - Unlikely
Lopunny - Unlikely, wait for the Easter event in 2021.
Audino - Unlikely
Diancie - Unreleased