I think it will have an impact because the Switch 1 is still fairly pricey, like it's not exactly a budget price.
Given that, you'd have to be pretty fucking stupid to buy a Switch 1 at this point (Lite model excluded). For $100 more maybe than what the OLED costs you'll be able to get a Switch 2 which will play Switch 1 software and maybe even enhance it on top of that you get access to the next 6+ years of Nintendo software content like the new Mario Kart game. And a bigger screen size too.
Anyone who was thinking of getting a Switch 1 at this point would be well advised to just wait a few months for Switch 2.