Regular postings resulting in more viewers? Perhaps, but then again that's his prerogative.
Regular videos do make a channel successful. But not necessarily because people will subscribe because of it. The vast majority of the reason why regular content makes a channel successful is because of how the Youtube ranking and search algorithm values channels who put out more frequent content. Hence you get ranked higher in searches, and your other videos get ranked higher, and so on it goes as a snowball effect.
And
that is the secret sauce to youtube success. h1386343 is grossly overstating how important scheduled programming is.
Yes, releasing a video at a certain time in a certain time zone (where your majority audience is) can get extra views faster, and that helps with the ranking algorithm too, but it's not a big part.
In fact, unless your vast majority audience is in one time zone, you can say it's pretty insignificant.
As for my audience, my biggest audience (the US) is still only 20% of my total audience. And they are spread over a big time zone anyway.
In 5 1/2 years doing this I don't think I've failed to put out at least 1 video every week. In fact my average is 3 videos a week over those 5+ years.
If I take a week off and don't produce a video, it will practically have zero effect on my subscriber base.