The revised Switch 2 that's showing up in Europe has been taken apart, and the screen hasn't changed, at least in the unit that was checked. Polish console technician modyfikatorcasper compared the new OSM-CPU-01 board with the original BEE-CPU-01 and found a repairability refresh, not a performance upgrade.
The NVIDIA chip is the same revision, and there's still 12GB of RAM, now from a different supplier. Nintendo also revised the motherboard and switched to a different fan, though nobody has measured whether that changes temperatures or noise.
The big change is the battery. It can now be removed without fighting the adhesive used in the original, which lines up with the upcoming EU battery rules the OSM revision was made for. Nintendo had already confirmed the European revision uses a 5,172mAh battery instead of 5,220mAh, and the console is about 10 grams heavier.
What it doesn't have is the Sharp-assembled LCD panel (LS079T1SX10P) that turned up on Chinese reseller sites back in June. That panel is the same 7.9-inch, 1080p size, and there's no confirmation it would fix the slow pixel response the Switch 2 screen gets criticized for anyway. The technician only had one unit and plans to check more, so some revised consoles could still ship with the new panel. A related model has appeared in FCC filings, but there's no word on the revision launching outside Europe.