Ok. No, I don't have the data, and I'm not going to scour the archives for it if I'm honest. It's a decision that was normal for long before I became part of the organization side of it, and that was the reason I was given. I felt no need to question it.
I don't know who prepares for the races and when. But I am sure we would ruffle more feathers than yours if we up and changed the track less than a week in advance.
The schedule was made public before the season started, so everyone could have seen what track layout we would be on. I don't see the giant issue. Yes there won't be a community setup or practice sessions, but a lot of guys tweak their own sets anyways. And if you don't like the GP circuit, no one is forcing you to race.