CD Projekt Red's Marcin Momot tweeted: "What if Geralt was going to step out of the @witchergame for the very first time to make an appearance in one of the upcoming games later this year?"
https://twitter.com/Marcin360/status/970994926677872640
People are speculating that it could be in Final Fantasy XV or Soul Calibur VI. If it's either, I just hope the deal means the game'll come to GOG. >:3

Inb4 Geralt embraces his feminine side

I could not possible care about either, nor do I have any idea what he'd be doing there. Then again I guess we are living in the age of popular culture auto canibalising itself to a ridiculous degree and having an actual reason to splice stuff together like that is no longer needed.

"Cawwadoody, Geralt Ops 7", I presume?

or maybe,

"Half-Life 3, Witcher Edition"?

or possibly,

"Fallout 15, where life is SO post-apocalyptic that it's medieval again"

HuniePop 2: The Destruction of Mör Daan

This I'd definitely play.

New addition to the Lego franchise.

Well, that certainly explains why Softporn Adventure was removed from GOG: there's a remake in the works featuring the horny heffalump!

So, basically that part of Doomsday with Malcolm McDowell as king of Scotland?

Pretty much.

Geralt will be activating his trap cards.

Alternatively, it'll just be Cyberpunk 2077. Hey, he did say non-Witcher game, not non-CDPR.

#JustTrollyThings

Soul Calibur having characters from other franchises is not unheard of, as they've already featured Ezio Auditore from Assassin's Creed as well as Yoda and Vader from Star Wars. I don't know how it turned out since I haven't played those games unfortunately, but I can see Geralt working as a fighting character.
Whatever franchise he pops into, I'm sure Ciri will have something to do with it.

I heard Geralt is to do a new educational video on why we should all have at least one client software installed on our machines, you know a bit like green cross code.

Perhaps a dark and gritty reboot of The Logical Journey of the Zoombinis?
"Zoombinis with iron swords can get past bandits, Zoombinis with silver swords can get past monsters, and Zoombinis with big breasts can be escorted past both by Geralt, who will then **** them"

One, it was just a "What if…?" question. And two, it could very well be simply a cameo, like sitting in some bar playing cards with Kenny Rogers and Bret Maverick. Doesn't have to be playable character in a game.

I think in general showing up in some other game seems like it would mean the series is over. In other words, The Witcher has retired into nostalgia, standing next to people for their selfies (fan photographs), doing autographs, waving and smiling… Showing up in some other game to help it gain some traction, or a maybe a new game in a series that has gone on too long and should have retired earlier, like those series with more than 10 sequels. Maybe get a kickback of funds in return for extending Geralt's comforts of retirement.