This assumption is being overlooked. I don't... "think" any people playing these games are using wifi/online features. In the past, Nintendo used online to detect people playing hacked Switches and playing games that aren't released yet, and then subsequently bricked their system, so I'm sure many people playing the early release are offline.
If there are any features hidden in online gamemodes like high tier raids, we won't know about them until release.
The only ways to play the game atm is either
- have a early copy, with only reviewers would have right now legitimately
- have a hacked switch and downloaded the rom
The first are unlikely to be leaking things out, and assuming the og leakers actually managed to get early copies, if they went online their Switch would have got banned from internet almost right away.
And the latter well... hacked switches also get banned pretty quickly, and if you're one of the few with a hacked switch not banned, you're definitely not going to get it banned by going online with SV.