With this Nintendo should be able to comfortably get the 3DS past the 70m mark within this fiscal year. Good announcement, because the only 2DS version that has been available before isn't exactly pretty and does not have a clamshell design.
Skimming a bit through this thread suggests that there are people who believe that this announcement could cut into Switch sales. That's not how it works though. This is going to add to the total of the 3DS family without taking anything away from Switch, so it can only be viewed as a positive thing.
If they produce enough units... Wherefore, lately... ;) Although, this is justifiable because of constantly missing the forecasts of wii u in its first two years ( which were somewhat high ), so they're conservative now.
3DS is scarce in Europe and the USA since Jan ( thanks to pokemon... ;) ), if these people who were going to buy one but couldn't find any and still want to become a 3DS owners better Nintendo produce a sufficient amount of New 2DS xl units...
As for the switch part, I agree...New 2ds xl is for people who can't afford anywise a switch or those who're waiting for a more portable handheld part of switch and of course considerably cheaper ( as switch is kind of expensive for the handheld console only gamer ) ! Those who can comfortably spend 299$, will go for the premium switch hardware and software and if they want they can buy a new 2ds xl later for the vast library of 3DS...
Also New 2ds xl is perfect for those who want the fairly better hardware ( I mean owners of old models ) of New 3ds xl ( the unusable browser on 3DS is usuable on New 3dxl, it even supports html5, it plays youtube videos smoothly ) but not at 200$...
What will be harmed for New 2ds xl is New 3ds xl... New 2ds xl has the same hardware with it, it's lighter by 60g, sleek and elegant! Also, it fixes a long time problem since DS family, the durability of hinges and the best thing, it costs just 150$ ( all that time people were paying 50$ for something they didn't desire/use/had problems with it. It's basically the best 3DS ever!
3DS and Switch can peacefully coexist!