I am questioning your statistics on that one. Billions of people got dusted, including at least half of Peter's class, so it is more than probable that those 6 got dusted. I mean some of them might not have been dusted, some might have survived and moved on. we don't know yet. However, regardless of statistics and anything else, if those 6 reappear in Far From Home that is what they will go with to justify their appearance