My understanding, based on the last game, is that our purchases of the Phantom Edition were to give access to the season pass via the BF Pro Token as a pre-purchase, rather than purchasing all items on the pass outright.
Weapons and gadgets that are not unlocked through progressing the pass should be available for unlock after the season through challenges (thats how it worked in 2042, anyway), but potentially any cosmetics or boosts etc that aren't unlocked will be missed (assuming that the season can't be played retrospectively).
I've not been able to have a detailed look still, unfortunately, as I've not been able to get on my Xbox to do more than claim BF Pro, but hopefully someone who knows more can explain things better.