Was this your Evo CC race?
In Zwiftpower you were 12th and only 2 riders in front of you were over 3.2wkg 20min avg in the final results. Using 95% of the 20min avg and the .1wkg tolerance allowed, those 2 are fine. The others that were over the category limits were auto-promoted to Cat B in this instance (some/most race organisers would configure to DQ them with UPG or WKG).
See the below thread and if you are game to read through, you will see that Zwift are going to introduce tools that will help deal with the low-life sandbaggers.
EDIT:
