seat choice on release

Hi,
I'm planning on booking seats for our trip to Orlando next May on release of return flights
(is this a good plan?), can anyone tell me when this will be? (7th to 20th May 2016).
I have also heard that Virgin block some seats out for Virgin Holidays customers, is this true as I'm hoping to book certain seats on upper deck
As you may be able to tell, I am a very sad OCD woman who's ability to wait is non existent
(in my defence, although we have been long haul many times, this will be our Virgin Virgin flight
)
Thanks, as always for any advice.
I'm planning on booking seats for our trip to Orlando next May on release of return flights

I have also heard that Virgin block some seats out for Virgin Holidays customers, is this true as I'm hoping to book certain seats on upper deck

As you may be able to tell, I am a very sad OCD woman who's ability to wait is non existent


Thanks, as always for any advice.