The game was announced at yesterday's Partner Direct:

https://www.vgchartz.com/article/465338/monster-hunter-stories-3-twisted-reflection-announced-for-switch-2-ps5-xbox-series-xs-and-pc/

Monster Hunter Stories decided to grow up from it's youngling casts of previous games it seems like. Probably craving for the older demographic of players here.

Also, there were a lot of Fire Emblem "vibes" coming from this one considering the seemingly warring nations at play here.
Honestly, I'm in again.

I still need to play the first two games which I have but dont want to start them just yet - want to play a proper MH game first (likely World) before I play a spinoff.

Most of the monsters in MH Stories have representation from earlier games than World. It barely has any representation in both games. If you want a sense of familiarity while playing Stories games, you're better to actually start with Rise I'd say.

Mainline Monster Hunter is absolutely worth experiencing; it's not for everyone, but if it clicks for you it's one of the most satisfying and rewarding gameplay loops in the business.

World and Rise are both great starting points.

Oh now this is one that I could get into, thought about buying Stories 2 on sale a few times but I was always put off by the tone of the characters and world. The idea is solid though. Count me in for one hundred percent certainty should it prove to run well with an 80+ aggregate.