It depends on what the NEET's habits would be.
If they go on forums or browse memes, eventually it will pop up in some discussion. Like this one.
If they play an online-based game, there's going to be other players there. Where the subject will likely show up in a discussion or as part of a joke.
If they spend time on youtube, eventually something will likely show up in 'latest news' on the front page. If you check, then it's likely that there is a channel featured on your front page that is related to whatever governmental institution is responsible for addressing covid in your country.
If they use websites that use ads, it will most likely show up there at some point. I know I've seen countless at least, on websites I'd never expected it.
If you at some point do go out, as has been mention you will see people with masks. If you for some reason don't want to ask anyone, you will end up somewhere where there is a sign 'Due to the current pandemic / covid, bla-bla-bla...'.
Governmental agencies send out texts that restrictions have been placed or changed.
The only way I see that someone wouldn't learn about it, would be to be a NEET as well as live completely offline and off the grid. In which case, it doesn't even matter.