On the other hand, I've been driving my OG Switch since release, and it shows, but I would not simply discard it because it has so much more hackable potential than the more current SKUs, potential I've been dying to explore, but haven't because it is my running device. If Sw2 goes the same route, maybe it's interesting to get one right off the bat to keep it for future experiments.

Depends on the price.
If the NS2 is $400 it makes NS1 pretty much redundant.
If it's $450 or specially $500, the NS1 should still have some life to it.

That will depend almost entirely on the launch price of Switch 2 and if Nintendo keeps all Switch 1 models at their current price.

If Switch 2 ends up being $400 like it has been highly rumored to be and the Switch 1 models stay the same price, that’s going to have quite a noticeable negative impact on Switch 1 sales. Especially the OLED models, because why waste money on the OLED model when you can just jump straight to Switch 2 for just $50 more.
Base Switch 1 and Switch Lite can withstand it more and those will carry Switch 1 sales until the inevitable Switch 2 Lite model, and that’ll be what effectively kills Switch 1.

If Nintendo actually bites the bullet and cuts the price for all Switch 1 models, that will buy the Switch 1 substantially more time… Unless Switch 2 launches at a lower price as well, which could effectively kill of Switch 1 sales right there.

It's about pricing. If Nintendo keeps the most expensive models at $300 or $350 while Switch 2 is $400 it won't bode well for Switch at all.
We'll know more in April once Switch 2 pricing is revealed and maybe we'll have Switch price cuts by then.

I think Nintendo will want to channel Switch 1 buyers of the OLED model + Mariko model right into Switch 2 though. They probably want a fast and big start for Switch 2 after the debacle of Wii U and the poor start for 3DS. Switch Lite they will probably keep around for kids and budget concious shoppers, but I think having the Switch 1 in the trailer literally transform into the new Switch 2 probably tells you were Nintendo's head is at.

The other thing is even if it doesn't launch until May/June whenever, the full blown marketing blitz looks like it starts April 2nd, which is only 2 1/2 months out with the big Direct for the system + Nintendo Experience Switch 2 events starting up and those will certainly end up being all over Youtube and Instagram and all of that.