Not exactly, you can now run the screen at 80hz and cap framerate to 40fps or keep it 90hz and cap framerate to 30 or 45, or run the screen 60hz and cap to 60. A lot more options.
And capping to 40fps on an 80hz screen eliminates the flicker you get running at 40hz on the LCD screen. So it'll have plenty of use, especially on a portable device.
And the DF review of it, the show Ori in the first few minutes, and it's of course a beautiful looking example of a hand drawn style game, with HDR support, and it is also running at 90fps with no fluctuations. Granted it's a game that runs on the Switch (at 60fps), but it's still a great game for anyone who hasn't played it, and one that particularly benefits from the OLED/HDR and also can run at 90fps on the device as well.
Perhaps more beneficial games will be all those boomer shooters and other FPS stuff like Doom 2016/Eternal running at 90fps, definitely an advantage there compared to 60.
They improved like 20 different things on the device, some major like battery (up to 12 hours), WiFI 6, the 1-of-a-kind HDR OLED screen, and some more minor like the better speakers, larger screen/smaller bezels, and so forth. And all for almost exact same price as it was before (think maybe it's an extra $10-20?). How is that not great? I wish other companies would do similar! The Switch sold for $50 more for OLED and didn't have nearly a tenth the improvements.