Well,, yes, except it sounds, therefore, like the OP's school gave the kids some study leave while they were doing assessments, unlike most schools where the kids had to attend normal lessons, and do assessments with none of the normal study leave.
Our year 11s left at half term and will come back for a week's induction which is 3 days longer than normal (and 4 more hour long sessions per subject for teachers to plan and provide) although in fact lots have said they won't attend the full week so that will cause disruption... They had to go then because :-
a) we have a rollover timetable so no real gained time for a lot of teachers and certainly no capacity to bring year 11 back. To get year 11s back we would have to jettison that and the year 10 and 12 exams
b) no one seems to have mentioned the workload to submit grades to the boards by June 17th. Ofqual chose this date, not schools. Extensive time is required to do this but I am sure some posters think this should be done after school every day perhaps? If Ofqual had set the date later, kids might have had later assessments, more in line with usual GCSES and left later/had study leave. But they didn't because their only concern ever seems to have been the workload of exam boards.
I didn't finish my spec for my subject, by the way. It will make not one jot of difference to A Level for the 5 kids pursuing it. And I don't see why they, or more importantly the rest, should be arbitrarily dragged through stuff just because. I do lament the extrinsic reward exam culture but we are where we are and it is often parents who focus on 'the pint' of doing anything.
Amanda Spielman also said she thought year 13 shouldn't leave.