It may be worth protecting a novice with strict guidelines but as we get more experienced and understand what too easy/too much feels like, the guidelines become more of a tip, something to consider if you feel burned out/something that was found to bennefit a considerable amount of people on the program.
Agreed. Well put.
The key word in the two examples is "must" - it may be true that you dont HAVE to deload/have rest sessions, it may be true that a deload week in 5/3/1 is part of the program and generally required, but what it is going to come down to is tweaking to get the balance between intensity, loading(progression) and recovery - and I can't think of a time when it would be more complicated than that - finding the balance is difficult, but the principle is simple.
I think the contradiction I perceived is resolved in the matter of intensity. Any 5x5 or 3x5 program for beginners and intermediates keeps you at or below 85% intensity, so recovery times are short. 5/3/1 shoots you up to 95%, and if you're moving heavy weights that's going to take a toll.
In my 3rd week of cycle 1, I doubled most of the heavy lifts, doing the full 5/3/1+ bench on press day, full 5/3/1+ squat on deadlift day, and full 5/3/1+ press again on bench day. At the end of the week I felt an accumulated fatigue, but it was gone early in deload week. I would bet if I did not do that doubling I could have just gone straight to cycle 2.
But for cycle 1 I wanted to play as written. Cycle 2 I won't be doing that doubling up, and I may do deload week only every 2 or 3 cycles, or as needed, or as it fits into holiday schedules, etc.