The announcement was made the week before Christmas last year that the new 11+ tests would be administered by CEM. IMO very poor management or sadistic.
Why is it very poor management or sadistic? The announcement had to be made at some point. It could be argued that doing so before a holiday period gave parents time to digest the news and plan for the nine months ahead. When is a good time? In the summer holidays when some would be away and would complain that others got a head start? At the start of the academic year when everyone is settling into the new year? After Christmas - too short notice for some? I don't think there is a time that would suit everybody so any date is as good or bad as any other. It isn't compulsory to read the guidance the day it is published after all.
As for the supposed notice for the upcoming 12+ test format, I support the short notice and don't see why it is disgraceful that we won't know the format of the test well in advance. Anything that levels the playing field by limiting the potential impact of coaching is a good thing in my book. Some notice is important so that children broadly know what to expect but weeks and weeks of notice isn't necessary. It might not be a popular view on here but there you go.