We don't know what you had said on there but, I can imagine someone had flagged or marked you as "spam". I know that there are people on that can't take criticism well online especially, on YouTube. I'm guessing that you said something that insulted someone? I know that some websites will not even tell you that you are going to be banned. A lot of websites change their Rules and terms at any time. YouTube and Google are partners so I'm sure it Rules and such as changed. I don't think it is a bug. I could be wrong, though?
I don't know you could try to take a look at this? *shrugs*

Here: https://support.google.com/youtube/answer/128036