I went through the system in the mid-80s. At the start, all QFIs were Sir, 24/7.
As we got more experienced, the younger ones were more relaxed and we were on first name terms with them, firstly in the Mess, then at work outside of the brief-debrief period.
As I progressed through the training system, the relaxation increased until by the time I reached the Tornado OCU, it was a very relaxed atmosphere because by then, there was no need for Sir in the cockpit.
I don't see how that is any different to what was on the programme.
In early training today, it's always Sir from brief to debrief, "You have control" "I have control, Sir" but outside that, there are no issues at all with first name terms, m8 or anything else. It works well.
What worked back in the 50s or 60s or later was relevant to then. It's not relevant to now. The students today are better than we were, the training is far more intense with far less time to master any given skill. And it works. Sorry if that upsets some.