I post this review and comparison to Pi 500 here because I too find this form factor very nostalgic like the article's author:
> For those of us that grew up during the home computer boom of the 1970s and 1980s, of which I am one, the form factor is nostalgic, and I can see some enthusiasts building their own home computer emulation systems using the Pi 500+, but, they could also do that with the $90 Raspberry Pi 500, or even the older Raspberry Pi 400. A few years ago, I managed to build a competent Commodore Amiga 1200 using my Raspberry Pi 400.
The actual product announcement: https://www.raspberrypi.com/news/the-ultimate-all-in-one-pc-.../
I suspect that many if the 1UP cabinets are just an SBC running MAME but I can’t be certain. I’ve never had a closeup look.