Yes, that‘s the official advice. I have heard it multiple times on the podcast and it is also the recommendation that TR employee @Bryce gave in the MV+/HV- thread. The first recommendation is to add Z2 workouts (“TSS fillers” in the post) and then increase the difficulty of workouts. I have heard it so often that it stuck in my brain (which is what learning is!), and I am applying it now to myself.
TR has repeated that people should start with a lower-volume plan (LV or MV), be consistent like a mantra, too. They have discussed the benefits of Z2 workouts numerous times on their podcast, including episode 196.