Well, to be honest here... they had to restore the service through third party services. But yeah... you don't need to pay additional fees to play online on old consoles. Even the PS3 and 360 didn't require so.
@xianc78 I used Xlink Kai to play BO2 on my modded PS3 many years ago and it's not the best thing ever. But yeah, if the game supports LAN gaming then yeah... it's a possibility.