categorizing gyms differently

bit of a weird thought... do you think we'll ever have a gym/E4 system that categorizes the Leaders based on something other than Pokémon type? for example, a region where the Gym Leaders each use a unique colour of Pokémon, or a different focus when battling (kinda like the gym trainers in Petalburg City), or all use Pokémon based on a specific animal (cat gym when?)

sun & moon showed that they're willing to change up the usual formula a bit, so is this something you could ever see happening? and what categories do you think would be cool?

I think this would be cool and another way to change up the gym forumla. A gym could use baby Pokemon or only Pokemon that evolve using evolution stones etc?

As cool as this sounds, I just can't see them changing up the formula of Gyms as they are. In Sun & Moon we got Kahunas and Trails in place of Gyms, but even then they were governed by trainers relating to a specific type.

I doubt it'll happen, that Petalburg Gym expanded idea sounds good though.

I keep hoping for the 1st gym in a game to be Dragon-type, as it resists all the starters equally but they aren't super-effective weak to it, and they can just use Normal-type attacks (just as most likely a level 10-15 Dragon won't have a super-effective attack against them, they won't have any Dragon / Ice attacks). Would make it interesting - still tough but not automatically sway you towards a particular starter like in most games.

There has been some mix-ups in the past that do hint if the people fits the theme, they're implemented ! (Ex. The non-Dragonite part of Lance's team, Bruno's Onix, Karen's poison types, Candace's Medicham, etc)

Like what Ana said, the possibility of getting rid of type speciality might be slim but mixing it up might not be

I think it's a real possibility seeing the recent change and how well received it was. I'm down for leader types being replaced by leaders with varied teams. It could end up being more challenging that way

In my hack, I'm doing dual-type gyms, where each Gym Leader utilizes two types (Brock is Rock/Ground, Misty is Water/Ice, Surge is Electric/Fighting). It usually leads to some better diversity than just using one type.