Coggan established the science behind power based training, and he isn’t a coach but coaches himself. Coaches don’t all agree on how to train.
Science agrees with him IMHO, go listen to the real experts on Inside Exercise or Empirical Cycling podcasts. For example I posted a paper here Weight training and FTP - #19 by WindWarrior that again agrees with what Coggan was saying.
My long rides usually have an IF in the 62-68% IF range. But hard group centuries are often in 72-85% IF range. And I did a double century at 67% IF. This type of riding is something Coggan doesn’t do a lot of (my understanding) - he races time-trials and I vaguely recall reading (on this forum) that he does a lot of shorter threshold or TAN tempo training.