I have no documented proof but this is my experience thus far:
As soon as retroarch was loadable in hbm I hacked my switch to play emulators, remaining in airplane mode the entire time I played for an hour that night and then my switch sat until kirby came out. I did a full format of my sd card via SD Card Formatter and updated my switch in order to install kirby. I played my switch for a couple months connected online, playing Rocket League with my buddy, then it sat collecting dust for a while. Sometime November 2 - 8, that week I deleted my network settings and modded again. Haven't checked to see if I'm banned, will probably do that after christmas. From what I gather so far Nintendo cares about NSFW, cheating, piracy, and blowing your fuses? Don't quote me lol. I've got a clean NAND backup waiting.
Add all of that together and you get how they've treated their product all along, starting with Tengen (Atari). Obviously Ninten-does what Ninten-do and may decide to ban anybody that has funky bits, nybbles, and bytes laying around on their system.
Edit: Apparently one user was banned for using a GBA emulator, not sure if they ever went online though. I didn't clear anything beyond my sd card and loaded nothing more than retroarch.