I am staying on this thread for the meantime because it has been great for support with my own DS and I hope I have offered some helpful advice from the other side as a teacher, too.
There will be measures in place. I too am worried for my DS who has been outstripping KS2 targets. I am also very very worried for BAME and disadvantaged students and the impact on them of historical underachievement and under predictions. I am worried that this year , by using statistician meddling, societal disadvantage will become more not less ingrained.I think maybe worrying about 9s is a lesser problem, sorry to say (and I say that as someone whose own DS may lose out on 3 of them)
Believe me, teachers are almost exclusively professional, credible and trustworthy and schools have robust systems. Within their own schools they will be well aware of patterns of high achievement in subjects both nationwide and within the school.
It is extraordinarily stressful for teachers. I will have to predict grades of 3 for some students whose lives that will alter. I will be predicting 5s for students who may have in reality scraped that or a 4 and will enter A Level routes optimistically and then crash and burn. Having to decide whether to suggest a 9 or an 8 for a few of my students is also angst ridden but not to the same degree. I am really hoping students who had very recently been awarded some kind of potentially transformational exam concessions will have this built in to predictions,too.
It's the most stressful time I can ever remember in my whole stressful career. One thing that marks all teachers out is a very critical self awareness of the impact of our jobs on lives. And all whilst worrying about our own health, our families, and the health and wellbeing of all the students we teach.
Please : trust us.