No wonder the College and WYO Director wanted to avoid the WYO rehearsal schedules being published.
It seems that a document was recently sent by the Bournemouth and Poole College to schools, entitled "Centre for Wessex Young Musicians - Key Facts", with sub heading "Communication and Cooperation between the CWYM/WYO and local schools".
Unfortunately, this document gives a materially incorrect picture of what has happened in recent terms (the only ones I have details for, because the rehearsal schedules were kept secret).
The full document (which is undated [why?], but seems to have been sent within the last few weeks) can be seen at the following links:
("Key Facts" page 1 and page 2).
I have annotated the relevant parts from page 1 here:
"there will only ever be one red rehearsal per concert programme".
This is not what has happened recently.: there were 2 [Update 12 May 2017, strictly speaking 3, although one is shorter at 1.5 hours] red (compulsory) rehearsals for the March 2017 concert programme, as you can see from this annotated copy of last term's rehearsal schedule (which I have to point out is copyright Bournemouth & Poole College):
This fails to mention the requirement that members need to attend at least 70% of the schedule. With 6 extra rehearsals during the spring term, that means in practice members *HAD* to attend at least one extra rehearsal even if they had attended all the regular ones. (Please see the bottom part of the rehearsal schedule screenshot above: I have just added the arrow, it is the WYO Director who put the requirement in red, to emphasise it to WYO children, yet makes no mention of this in the document sent to schools).
There are other things wrong with the College/WYO's "Key Facts" document, but the evidence above is sufficient to demonstrate that the document cannot be relied upon to give an accurate picture to schools or anyone else.
(Postscript added 1218 UK time 6 May 2017): the claim that there is only ever 1 red rehearsal per concert programme was not only false with regard to the 25 March 2017 concert, but also for the 16 Nov 2016 (Schools Prom) concert (red rehearsals on 2 dates: Sat 12 and Tues 15 Nov 2016), and for the 4 Dec 2016 concert (which actually had 3 red rehearsals: a double amount 0915-1530 on Sat 3 Dec and a full 3 hour red rehearsal on the morning of Sun 4 Dec 2016).