Well others have said that phone representatives have confirmed that the ban is just the standard 15 days, and your logic just doesn't fit in with what we've seen so far.
Did the other users have a NNID tied to their systems and also asked about the error code they get when attempting to access Miiverse?
The reason why the rep told me it's a perma-ban is because error codes:
002-0102
"This device's access to online services has been restricted by Nintendo."
022-2812
"You cannot access Nintendo Network services using this system."
Indicate a perma-system ban.
If it was just the one code, then it may just be the 15-day ban. The rep has also stated that there have been a lot of inbound calls about this issue.
@Majickhat55
I know for a fact that I never went accessed any of Sun or Moon's online features at all while playing. When you go into the festival plaza, it goes into local wireless mode.
I can't speak for everyone else.
While Nintendo can't tell the difference between a CIA and a legit downloaded game, they CAN tell that you are playing a "digital copy" of Pokemon Sun and Moon before it's out, which is impossible according to them. Also people that used the actual cartridge to play that they got from sources that broke street date have also been banned.
I don't care if you believe me or not, but this is no reason to call people that have clearly stated many times that they have never accessed Sun or Moon's online features at all, stupid.