Well, I use the Royce's diagram in the same fashion that he did 50 years ago, to show what is wrong about Waterfall. And I even include the posterior diagrams in which he shows what really happen, including feedback loops etc.

Royce in fact intended to change how Waterfall worked. He did not agree, and he even proposed some techniques very close to what we understand agile.

I have more in this other comment here:

https://medium.com/@drpicox/ok-i-reread-it-and-i-now-understand-where-is-the-missunderstanding-60f0048d163c

Thanks for the feedback!