While I agree with the sentiment, my impression is that the GP's point is about memory safety rather than performance. So yes, this applies for common patterns like per-frame memory in games, in which case the "it" is the arena. Otherwise, as a general rule, profile first, then optimize.
The latest edition (7th ed, 2015) actually uses 4.5 as well. AFAIK OpenGL hasn't changed too much since 3.3, certainly not to the point of being irrelevant for learning.