OK, yes, it's a very recent Notex. But equally, how many people know what's now required on a SEP revalidation LPC? Or whether the visual navigation section is still required if the applicant revalidates a IMC Rating on the same flight? All Notexes and other changes over the preceding 3 years should certainly be briefed at the seminar. Somewhat more important at revalidation time than 'Human factors in the teaching and learning process', I would wager!
If someone came to us having been taught other techniques, we would assess him/her first before deciding on the course of action. If the final approach and landing technique is OK, we wouldn't re-teach 'point and power'. We would correct any errors, of course, and would certainly teach Standard Closing Angle because this keeps people closer to track than other techniques and is less likely to lead to airspace violations as a consequence.
Some people are truly awful though. A so-called experienced FAA PPL holder was so utterly dreadful that we couldn't send him solo. He let the aeroplane fly him rather than him controlling it; I can only assume his continued existence as a pilot was more by luck than by judgement.
The proof of the 'CFS' techniques is that most students find them easier, solo earlier and are more confident when flying navigation exercises. That's good enough for me!