I am in the exact situation and that just doesn't make any sense. It would cost less to just buy the game as a non-upgrade ($40) - which we know all accounts can access- than to pay for 2 upgrades ($50). Right now only the master account can access the upgrade that we paid for.
I am in a slightly similar position regarding DLC across accounts. I bought a Japanese version of the game and wanted to upgrade to Celebration. If I purchased the upgrade on my wife's Japanese PSN account, it would not work on mine and I am not levelling up again. It makes no sense at all and is absolutely fleecing people. Imagine if you have a couple of kids who play the game and share a PS4 ... multiple purchases. EA's greed is beyond measure. It is a great game, but the mess that has surrounded it - initial launch, the loot box fiasco - this issue with DLC - is rotten! Also, they are losing money because a lot of people either will not, or will be reluctant to buy it due to the account issues. So annoying!
