I see Pro Sony and Microsoft on there all the time, though. Hell, I post a lot of it. Never had anything happen. I even said that the PS3/360 versions of Black Ops II had 3D and the Wii U version didn't. I say stuff like that all of the time without repercussion. This is actually the first time I've seen Nintendo react on this.
I got in trouble for posting my PSN ID/Gamertag (which is also my Nintendo Network ID) and a couple of other things and since somebody has been reporting any comment I make about a game as a "Spoiler" my Miiverse activity has dropped considerably. Still was a great place with a fun community, though.