Well I have been wrong before, blaming my bottom bracket for what turned out to be wheel flex (in the first, warranty returned wheel. The warranty paid to build the 32 spoke ). The frame is a 2017 Spz Roubaix btw. I am pretty sure it not the frame though because when the stock was new and the mavic was new, things were quiet (3 months stock, a year for the mavic which I bought while the 32 was being built). Spokes flexing against each other sounds like any other creak or click though so I could be wrong again.
I am pretty sure my front wheel is flexing now (retensioned last Oct) because what I hear with it is the brake pads touching the disk (out of the saddle, 38x34, 8% or above grade) but it goes away when I sit down (faster out of the saddle efforts have enough wind or other noise that I haven't noticed it).
p.s. the 32 spoke rim was a DB511 (not 520)