Well, I was kinda having an internal debate because genre discussions are really messy. Keep in mind my list is limited to my own knowledge and not exhaustive. We can get into things like subgenres: we say JRPG as distinct from RPG - that would be missing from Sony's genre list we could include: CRPG, Tactics RPG/SRPG (Xcom family and Fire Emblem-esque respectively), MMORPG (Traditional like WoW and looter shooter style like Destiny). The monster hunter RPG like Pokemon, Monster Hunter, Digimon, Yokai Watch, TemTem could also be distinct. Things like sports are tricky too because if you're looking for genre diversity someone interested in football is not necessarily interested in hockey, or cricket, or whatever even if those would all be grouped under sports. It seems unfair to hold that against any publisher though. A more meaningful divide is between arcade sports games (Mario Strikers, NBA Jam, extreme sports games like Tony Hawk and SSX) and more sim sports games (MLB The Show, Madden). Since SingStar is dead we can say rhythm games.
Theres also a bunch of genres that have a more PC origin that aren't represented. Sim games, which cover a WIDE variety of things between all the theme park sims, various job sims like Euro Truck Simulator and Football Manager, and weird things you can't really place like Kerbal Space Program. The whole survival sim thing that's big now like The Long Dark and The Forest. Immersive sims like Deus Ex and Prey. 4X games like Civilization and Stellaris. RTS games. Stealth games (as opposed to games with stealth in them). Deck builders. MOBAs. Battle Royales (some don't consider this a genre though). Visual novels (you could count David Cage games here, but those are more adventure imo). Some games are difficult to classify- there's been this rise in factory games like Factorio and Space Engineer. The puzzle game genre is huge as well, but I'm not well versed in it.
That's about all I can think of, and I'm sure its only a fraction. Though I did get pretty granular, I wouldn't say any of these genres are particularly obscure. A quick peak at Steam's top 100 games shows a diversity far greater than any publisher out there and shows how successful these weird obscure genres can be.