The hackaday post is from this year, and talks about forum threads/guides from 2019. I would guess the author only learned about it or decided to write about it now.
Even if it's not that useful to people nowadays, it's interesting to learn such a thing is possible.
>threads/guides from 2019.
2018, April
And? Submissions talking about the architecture of the Game Boy don't need to be tagged 1989.
Mentioning the Game Boy would date it implicitly, they don't make Game Boys anymore. Intel is still around.
"they" Nintendo doesn't. But "they" random people from the internet make FPGA motherboard of Gameboy that is compatible with factory buttons, case and accessories.