For what it's worth they have never claimed to have them in stock that I've seen. It's effectively a pre-order for when they get stock.[/
I am not sure where you live , but in europe i ordered 1 from parrot.com on 2nd of august. Put it in the shopping basket and witin 4 days i received my spare battery in the netherlands ( i think it was sent from france) .
Yesterday i checked there website again , was planning for a third battery and it was mentionned again “available soon”. So i think the first batch they produced was sold very quickly