As far as I know, Rabbath was the first person to introduce collapsed fingers as "correct".
I think adherence to the concept of what is taught as "correct" is way overrated, especially because it can become a snapshot from a frozen moment in history. Knowledge and culture evolves. If it didn't, women would still not be able to vote, the NBA playoffs would be rife with two handed chest passes and centers who can only play with their back to the basket, and people would still be smoking on airplanes.
Regarding technique, I would advise players to try everything that you see others doing that seems to work, keep what works for you, and throw out what doesn't. Pay attention to the details and practice slowly, making sure that what you are doing is healthy and sustainable for you. Don't ignore pain. Also don't embrace dogma from an older era without questioning if the subject and substance of the dogma has evolved since it was written on a stone tablet. As always, EEMMV, and EEMWCB.