Some Evernote users on the free tier received this popup message
As for why the website doesn’t mention the limit on free accounts to 1 notebook and 50 notes, Evernote says that it is because the change has yet to be made official. The test using these limitations on free accounts has been disseminated to less than 1% of its free users to see whether they take the bait and pony up for a paid account.
Evernote did say that the free account being tested would not limit users from editing, managing, deleting, exporting, or viewing their existing notes even if it is more than the new limit. What it will do is prevent these users from creating new notes unless they open a paid account. The big question is whether the free users take the plunge and become paid subscribers.