Youtube exploit ?
 

I uploaded a video on youtube, and there was a comment already like second after, so that smelled like a spam bot.

So i checked profile. which is this: https://www.youtube.com/channel/UC3M...46ryw/featured

and it looks like they mimic traptown account which is real and somehow show uploads of traptown as their own, despite not having actual uploads at all. Any clue how is this happening ?

Voodoo. Definitely voodoo.

I think he's just made a playlist named Uploads using the official videos and customized his channel to display the playlist on profile front page.

Yes but when you here: https://www.youtube.com/channel/UC3M...6ryw/playlists
it says no playlist created.