Is this referencing some unexplained relation to the post or just vlog spam?

The channel name is the same as the github username of the deno db author, so I think it is actually related despite the content not seeming to be

Edit: And the authors website links to this channel

Same person. Their GitHub profile is linked from the above Deno repo, and their website is linked from their GitHub page, and that in turn links the Youtube channel, in addition to the obvious common user name.