People are upset because they feel like Sony got exclusivity on the game too. But the Devs came out and said that they felt the Xbox isn't selling enough to warrent extra dev time to put the game on that console and they don't wanna be part of Gamepass either. So they only ported to Playstation simply based off market share.
I mean, if the cost of getting on Xbox is I have to put my new release game on Gamepass (which will immediately make it more or less free to my entire (for BG3) PC/Windows main demographic, it'd have to be a hell of a truckload of upfront money. Releasing on the freebie (obviously not completely free for the end user) side makes some sense as an indie upstart (ie Rocket Leagues initial swing on PSPlus) but not when you're working with your established "brand"
I've said it before though, Larian may well make a solid game. But the very conceptual foundation of a "Baldurs Gate 3" just screams pointless cash grab given how conclusively the saga ends. At best its a tradeoff of some integrity to get a bigger budget or access to the D&D license for something they wanted to do beforehand, but it reeks of Matrix 4-esque nostalgia grabs (except the Matrix was probably more open ended if they hadn't tried to recycle Neo)
AS far as it releasing on consoles being a surprise is? Not really. The current and last gen consoles are so computer architectured that they're basically just prebuilt PCs with a curated selection of games guaranteed to be compatible without fuss. Both Xbox and PS have had KB/M support for coming on 7 years now for anyone that is bothered by that. And all the other Enhanced Edition ones have been ported already (I remember waxing nostalgic about Neverwinter Nights being on PS4 lol, though of course it doesn't have the toolset which was the entire point)