Yeah, maybe. But also the official SDKs are pretty good and you get support from Nintendo. It seems like a pretty big risk to use an unsupported SDK... for what benefit?
I don't have access to Nintendo's SDK so I can't compare directly, but the article cites an inability to map executable pages. libnx supports this (but of course, this is moot if Nintendo wouldn't let you ship it). But the main benefit is being able to talk about and share your work without worrying about violating an NDA.
The OS can do it, and some Nintendo titles on the Switch do use this capability, but I have talked to Nintendo directly about using it, and it's a hard No. I can't even use the JIT feature purely for dev.
This doesn't surprise me much, but does Nintendo state this explicitly anywhere public?
If Nintendo chose to sign an application developed using a 3rd party toolchain, there's no technical reason why it couldn't run on retail consoles.