Basically we need actual facts. It has been stated on this thread that the "new" pellets are Express profiles weighing in at 8.44grains but manufactured to within 1milligram (0.001g) tolerances.
It may very well turn out that they are Exacts, weighing 8.44 and indeed in a tight mass distribution and the poster who indicated that they are Express is incorrect. Also maybe there are Express with a tighter mass control.
Time will tell.
and no - I never heard of any such chrono fail resulting in a lower placement. if a chrono results in a red card the equipment is removed from the course and the card voided. A yellow (over BFTA but under FAC) is allowed to continue but future GPs would be in doubt if the yellow is handed out again that season.