It's entirely up to the game organizer. I would hope though, if a greater majority of people were reading higher than normal that there could be exceptions to the rule. weather conditions can cause the guns to shoot higher from one day to the next, even AEGs.
I've seen as much as 20 fps difference on AEGs from one day to the next.
As much as 50fps from morning to afternoon on a kwa mp7 which is propane
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.