It's definitely worked. Focusing all that new enthusiasm on fundamentals makes them tricky for the rest of us to deal with, which I imagine builds their confidence as they go too. The situation for beginners can be overwhelming enough without information overload as well.

Starting by teaching new grapplers fundamentals of take downs and positions, and transitions, is a very viable way to build very skilled grapplers.
As well, experienced wrestlers convert very efficaciously into skilled submission, grapplers, with a very short learning curve for learning submissions.

Of course it is not a „no go“ or some kind of hidden knowledge.
But all the starters have definitely to understand what good or bad positions are and the meaning and importance of transitions first.
It is the same like in other sports, like soccer i.e..:
If You have 90% possession of the ball, the statistics tell You that You will win the match.
-If You constantly work for a better position and Your effectiveness is high enough the sub will follow anyway.

I keep meaning to watch that vid, as I like the stuff Chris puts out. I also like sparring drills without submissions: since I saw Christian talk about it in a class a few years back, the "pass on top, maintain on bottom, only open guard but no sweeps or submissions" drill has been a key part of my class warm-ups. I more recently added in "bottom person is trying to recover closed guard", so both people have a goal.

My beginner classes have a position of the month, cycling between side control, mount, back, closed guard, half guard and open guard. There will be a few core classes I include every time (e.g., basic escape from the back), a broad selections of classes I switch in and out, plus a few new ones I add each time to keep things fresh.

BJJ can have a steep learning curve, I find that focus helps even it out.