What is a published note?

Publishing a note makes it readable by anyone with the link, including people who have no Hitaji account.

It is a different thing from sharing, which grants named people access. Publishing grants the link access, and a link can travel.

Treat it as putting the note on the open web, because in effect that is what it is. Attachments can be held back from a shared note if some of its files should not travel with it.