It's interesting, all of us interpret it based on the YouTube bubbles we are familiar with:
I first assumed they were referring to the "I have just figured out a secret, little child, and I'm deigning to share it with you" type voice that Johnny Harris and people making videos of that ilk put on.
Then I thought maybe they were talking about the YouTube voice people like Connor (CDawgVA) and Ludwig put on, which is a mix of the "hype" voice you mention and a sort of 80s radio presenter voice.
The conclusion is that there's no such thing as a "YouTube voice" that the GP comment mentions, it all depends on which bubble of YouTube you're familiar with and extrapolate to the whole of it.
It may also be just how youngsters talk nowadays, because my teenager's friends have the YouTube voice. (Or maybe their excessive YT consumption is affecting their speaking style.)
I first assumed they were referring to the "I have just figured out a secret, little child, and I'm deigning to share it with you" type voice that Johnny Harris and people making videos of that ilk put on.
Then I thought maybe they were talking about the YouTube voice people like Connor (CDawgVA) and Ludwig put on, which is a mix of the "hype" voice you mention and a sort of 80s radio presenter voice.
The conclusion is that there's no such thing as a "YouTube voice" that the GP comment mentions, it all depends on which bubble of YouTube you're familiar with and extrapolate to the whole of it.