There is always a danger when parents think they know the pecking order within the school that many candidates are put off applying altogether!
DS's school also has had a downturn this year in offers for both Oxford and Cambridge. There are some surprise rejections and surprise offers, again leading to raised eyebrows in some quarters. DS will be going through it all next year as he is year 12 and it has given him hope that as one of his schools probably so called lesser candidates that he has a real chance over the boffs!
I am glad to see the Colleges are treating people as individuals and not "cloned, I have ticked all the right boxes" applicants.
No-one other than the interviewing panel knows how well the interview went. Sometimes people think they have fluffed it because they can't provide a definitive answer whereas they will have been judged on their thought processes. Others may think they have done well because they do confidently provide the answer, without realising (a) it might not be the answer and (b) their reasoning behind the answer was not actually sound at all.
It has definitely been a strange year and I think there is a lot being done to address the "it's not for the likes of us" applicants.
Well done to all those who have successfully received offers and I hope you achieve whatever grades you need to meet them.
Commiserations to those that didn't. There are some excellent courses that can be tailored to your own interests out there. If on reflection you don't think your back up choices were right take a gap year and reconsider options, including whether to reapply to Oxbridge.