the friendlist seems to be intact, i haven't looked into the NNID though, i assume the NNID is no longer on the system because if it was i can't imagine it letting me do anything with it if my NNID is banned
Ya gotta take localfriendseedcode_b from a non banned 3ds and inject it into the banned one. But then nobody really knows what that file does and it's advised not to mess with it and wait out the ban. It's most likely just a 15 day ban. But this is the internet and a half asleep me talking, so I could be wrong. If you wanna mess with that thing, get it with Decrypt9.
only ps5 updated to latest firmware can go on psn, jailbroken ones just don't use psn or they risk getting flagged or banned, altho spouting profanity in online play alredy does that