If an user buys additional content for a game in my PS4 (and they have it activated as their main console), do all the other users get it as well?

My brother and I bought Horizon ZD on the summer sale and now we want to pre-order the DLC, and his account is the one with a PS Plus subscription, which will make it cheaper. If we buy it in his account, will I be able to play on my user too? We only have one PS4, so naturally we both activated it as the main one.