I'm guessing this new tech will be quite costly to begin with?

They cost more, yeah. Probably come down as they become more widespread.

I'm not gonna say "don't get a single-layer OLED display"

that's a value call for you. Just saying that you kept the last one for eleven years, and if you plan to keep this one for another eleven years, you might want to keep potential for burn-in in mind, given that we've got significant OLED display longevity improvements happening. Depends on a variety of factors, like brightness of display and whether you have static elements onscreen. For some people, it simply doesn't matter.

I kept my last monitor for about 15 years, so I'm inclined to favor longevity increases

switched because DVI was pretty much dead. But lots of people aren't gonna do that, so...shrugs