Nintendo did a lot more with the OLED than just change the screen too. They’re pretty similar types of upgrades, lots of little improvements for more premium build quality, doubling the memory, improving chip efficiency for a tiny performance bump, etc.
Probably depends on where you are. My brother got a notification that he’ll either get his next Wednesday…or the following Monday. I don’t know why there’s a jump of five days if the Wednesday delivery doesn’t happen, but hey, that’s what he told me about when he’s getting his.