An incomplete list:
- Fantasy today is often cozier and lower-stakes. Characters are more likely to want to open a coffee shop than build their own castle in the wilderness.
- Resorting to violence is what the villains do, not the heroes.
- It often looks like fantasy Asia, but it almost certainly doesn't look like fantasy Europe.
- It is diverse by default. And that's much more than classic D&D cantina diversity. There will be people from across the LGBTQIA spectrum. There will be disabled people. Neither of these will seem weird or objectionable to residents of the world except, again, for the villains.
- Magi-tech will be common.
- Environmental issues may play a big part in the setting. Good characters will be aware of the impact intelligent beings have on their environment and will be expected to not wantonly despoil.
WotC has tried a lot of these elements in isolation, and Baby Boomers and Gen Xers on this board have often
howled with outrage. (Not WotC, but look up how people responded to the very notion of miniatures of characters in wheelchairs.) I can only imagine how they'd respond to a setting with all of them.
But the statistics don't lie: The audience is overwhelmingly Gen Z. Putting out settings to make the tiny Gen X audience happy instead of focusing on Gen Z is an insane business practice.