Some coops go fast, but there is really no way to handle that other than first come first served. For new stuff, order quantities are limited to allow more folks to participate, but the coop manager has to decide how big a coop they can handle and cut things off at some point.
If you did give notice to the date and time, the coop would fill up in minutes rather than hours and the folks that missed out would still be upset.
There has been a lot of talk about this in the past and no one has come up with a fair and manageable solution that is any better than the way we currently do the coops.
The best advice I can give is don't set your plans around getting the latest hardware...