Sudden removal of sets in Yr8 -- and they haven't even told us

[FriendlyLadybird]

My Yr8 DS told me (in a 'by the way' fashion, as is customary) that his school is no longer setting by ability for maths and science, as they did last year. He's in completely new classes for everything (another thing that was just sprung on him) but felt the different dynamic in his science class and so asked the teacher. I have written to the school to ask for more details, acknowledging the possibility that he got the wrong end of the stick -- although, to be honest, that's unlikely.
Are DH and I right to worry that it is going to be very difficult to teach these subjects effectively in large, mixed-ability classes? DS made fantastic progress last year in maths and really enjoyed it (which he hadn't much at primary school). Is that progress going to slow?
And are we right to be pretty annoyed that there was no prior warning or explanation of this move?

[appletreeinthegarden]

If your son was in top set last year then I think you are absolutely right to be concerned. A teacher who is having to teach a huge ability range is inevitably going to have less time available to teach the "high end" stuff. If this were to happen at my children's school, I would (a) complain to the head, and (b) try to find other like minded parents and encourage them to complain too.