I still think (based on livestream comments and FAQ) that:
baseline for subscribers will be 40 slots. Any unlocks will bring it above 40 - up to 50 slots with 10 unlocks. preferred are going to get 16 slots, whether they have unlocks or not Unlocks will be in effect only when you are subscriber
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If all above is correct, then for majority of subscribing players, 40 slots will be more than sufficient, and they don't need to buy any unlocks.
On another hand, BW, being sort of used car salesmen, would want to sell as many unlocks as possible on uncertainty, before expansion hits the servers.
So people, speculating that they would have to buy more unlocks to bring available slots to 40, are playing into it.
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