Online services for earlier consoles like the Wii were more basic, and IIRC in some cases were developed and maintained by third parties, not Nintendo themselves? I understand wanting to get rid of that overhead especially if it wasn’t driving incremental revenue.
But now the Switch is more intimately tied to online services for buying games and add ons. The most customer-friendly approach would be to keep backend services running indefinitely. Basically consider your backend to be a platform like Windows or macOS and maintain and evolve it indefinitely, keeping older consoles alive as long as possible (and continuing the ongoing revenue stream from older consoles, even as it shrinks over time, to at least cover cost.)
It seems like they have to do something like this to support downloadable games, at least with the online shop. I wonder how they’ll handle it.
I read a rumor that the successor to the Switch is expected in 2024 or 2025. And we picked up a Switch a couple months ago and I chose to buy all games as digital download version. And I remember the backend for the Wii being shut down. So this has been on my mind recently.