I fail to understand the bickering about insignificant details.
The intensity of the phenomenon is related to Mach on one hand and the deceleration rate (here 1 kt/sec). Since the values are different for flight AF447, it is likely that there was a significant and rapid decrease of the effects, which explains that the technical crew did not mention it and the cabin crew did not call the cockpit about it.
(my bolds)
I would still point to the same above phrase, questioned originally IIRC by Chris Scott.
That decel rate used is also used for the manual stall QTGs in the FFS, from which, among other things, the buffet levels are tuned. The entry rate dependent variation would seem to be of some 'significance'....at least training-wise if different in a 330.
One would think striving to avoid the training caveat: 'the same, except different' would not be unreasonable. Accuracy and fidelity for training or 'just' a 'gee-whiz' flight are not insignificant IMHO, especially if purported to apply over a broader range. Expert extrapolations with caveats, as valuable and as conducive to happiness as they may be, are still in this case, 340 to 330 extrapolations.
In 45+ years of flying, I have never discounted any detail.