You are paying to unlock the characters right away when they are released. The game launches with 7 characters unlocked, by playing the game and leveling up your personal rank or by completing specific challenges for specific characters do you unlock the other 18.
Sounds like the other 5 will be the same way: Obtain Rank 60 or kill 1000 players characters to unlock Character number 27.
Buy buying the season pass, you do not have to unlock the characters, they will automatically come unlocked for you when they are available.
If people actually researched, Gearbox stated last week their intent when it comes to DLC.
Everything that could affect the Balance of PVP will be free content for everybody such as maps, characters, modes, etc.
Anything cosmetic or content added to PVE will cost money, whether it be in-game currency or real cash.
If you are up to date with Gearbox’s announcements, the way they worded it would make sense. If you are not up to date with Gearbox’s announcements, the way you and your friend perceived it is understandable.