To be fair, this is a typical Battlefield Scenario. I haven't seen them post it on the official BF channel to try and keep the hype - instead they keep saying "Check your emails constantly" - Well don't bother.
I follow the Global Community Manager having had dealings with EA events in the past.
Please READ this tweet and lets put an end to the threads.
When will the codes sent out?
No exact time has been given, but it will be the 30th.
Can I pre-load?
As per the tweet - no preload for the BETA
When will it appear on the relevent Platform store?
When each store updates, which varies on region. The PS4 store for EU has updated at around 9am/10am GMT previously.
Now please, for the love of god - let's stop asking and just wait!