I did what you suggested above, twice. In both cases, there was only one previous version in the note history, and that version of the note had only the note's title, nothing else. And, in both cases, the encrypted text was not in the note history. So, I guess for users who will go to the trouble of disconnecting from the network before writing a sensitive note, then that will work, but that type of workaround is clearly an indication that Evernote is not the right product for anyone who has any notes that are even remotely sensitive. More realistically, users won't decide a note is sensitive until after it's written, and they'll probably write it while connected to the Internet (while on a Zoom call, for example), so the opportunity to keep the note private is basically gone forever since Evernote will have it, well, forever.
Like some of you, when I used to see messages like mine above, I rolled my eyes and thought, "How silly, what do they have to hide?" Well, for various reasons I'm now completely in the other camp and now fully understand why something we didn't think needs to be hidden really does need to be hidden. Better safe than sorry is an understatement, and you shouldn't learn that until after it's too late.
As much as I wanted to go back to Evernote, and even embraced the new version that so many loyal users seem to dislike, I'm afraid I have to look for an alternative.