Right, @Newname576 , I see your concern, which wasn’t remotely apparent from your OP which I responded to!
@TheOriginalEmu’s post sums it up for me. Blind recruitment is designed to do several things. It’s trying to level the playing field for those entering the job market after decisions made at 18. Don’t forget that for every brilliant young person who makes it into Oxbridge there are also the ones who don’t, but could have done. Some of them will go to other big name universities and others not, depending on their circumstances. Three years at Oxbridge doesn’t erase their potential. It’s still there, waiting to be seen.
But also academic brilliance may not even be relevant for many jobs. If your son has career aspirations for a certain field, and it’s something that’s right for him, then his strengths in that will be what matter, not what degree class he got at all.
Blind recruitment is trying to drive diversity. Your son has already smashed one barrier. He has succeeded on his own strengths. He will do that again for the right job. Plenty of employers still have totally open recruitment where your son’s achievement will be immediately apparent. Those that don’t, who are running big schemes, have thorough and multi-stage processes. The first hurdle is an application form, to get through the door, but after that, candidates succeed on what they bring into exercises, tests, group work and interviews, to show that they can succeed in the field, whatever university they went to. No one can take human bias out of any process but unless your son is applying for jobs that are totally wrong for him, he will bring the same qualities that have seen him succeed so far to the next stage in his life.