Yeah been there too.
I'd recommend you to be careful going forward. In my case I was banned from Splatoon 2, before I was eventually banned entirely on my Switch, and I wouldn't want to see that happen to you as well.
Also while it might not of been directly linked to the ban of my Splatoon 2 account. The game is still owned by Nintendo, so you can't ignore the possibility that your console is prioritized for investigation, once you've been exclusively banned from a Nintendo made Online Compatible Game. Just food for thought.
There's absolutely no proof to back it up, unless someone knows the inner workings of the flagging system at Nintendo, regardless still be careful.