Nothing to get worked up about. I doubt it's true though. Ellefanning may have their sources, but Nintendo is probably just making you paranoid. I couldn't imagine someone being able to view your screen. WiiConnect24 turned off helps those paranoid about Nintendo seeing them playing a game. As for the internet channel, as stated before, your history can be seen at numerous places already. See, if Nintendo wanted to catch the homebrewers, they wouldn't post this information immediately. Every homebrewer knows not to update because the HBC needs to change versions.
It was completely useless.
... Then again I manage to make a conspiracy about everything.