All the fuss derives from a mashed first-person shooter compilation made by someone called
Hoby who has 96,000 subscribers on YouTube
In the clip, someone off screen repeats high noon several times (click on link). I believe high noot noot is a mock imitation of that expression, and has probably become a catchphrase among hardcore gamers.
Toward the end of the video compilation, the shooter turns around and reveals himself to be Pingu. This is the link of that precise moment (02.47). Warning: keep the volume down on your speakers.
I just limited myself to reading the semi-literate replies on YouTube page