It reflects poorly on the FIA that all cars arent check after a GP and its random sample. Also why didnt FIA check plank wear after the sprint? They would have started to see the wear and could have instructed ferrari and mercedes to raise the floors.
Mistakes happen. Any suggestion it was done on purpose for performance gain is tin foil hat conspiracy.
https://www.the-race.com/formula-1/the-rule-breach-that-led-to-hamilton-and-leclerc-austin-dsqs/
"...However,
there’s nothing to suggest that the Mercedes or Ferrari were running in a ride height range that would have transformed their pace either way.
Teams are also cautious about plank wear because it is almost inevitably an instant exclusion,
so it would be absurd to deliberately take the risk just because it confers a performance gain..."
"..It’s reasonable to contend that
neither Mercedes nor Ferrari would have tripped up on a normal weekend with three free practice sessions.
Mercedes was convinced this was what had gone awry in its case.
Trackside engineering director Andrew Shovlin added: "Unfortunately, it is one of the pitfalls of the sprint format where we have a solitary hour of running before parc ferme.
"Without running at a race fuel load in FP1, combined with a circuit as bumpy as this and the parts of the track where the drivers have to put the car during the grand prix, have contributed to the higher than expected wear levels."
Not only do sprint weekends leave only a single practice session rather than three, but the
set-up is locked when the cars enter parc ferme at the start of Friday afternoon qualifying.
That means subsequent changes would have led to having to start from the pits. Effectively,
Ferrari and Mercedes were locked into this outcome on Friday.