I wouldn't really call that a misconception, per se. Waterfall pretty much was the only thing before the 1990s - it just didn't have a specific name or brand associated with it, so to speak. After all the default of doing anything is to do it in order from first to last... which is just, well, Waterfall really.

Agile 2 can certainly be described as an improvement, but it remains to be seen if having so many 'Principles' will cause it to fall victim to the same problems Agile has fallen victim to. We shall see.