Crown
¯\_(ツ)_/¯
What you're describing sounds like an old feature from several years ago called "Youtube shows". It allowed channels to create a TV series with seasons and episodes. The advantage was they were given priority in the search results. The feature was by invite only and channels had to first prove that they were capable of making regular good quality content. The feature was discontinued a couple of years ago but channels who had already been approved for it were allowed to continue.
An example channel with this is "Annoying Orange". And here is their "YouTube show" (essentially a special type of playlist) - https://www.youtube.com/playlist?list=ELD3iEbOBdm3A (Notice the dates. This is from 2012 so it's not a new feature. Also notice if you click on one of those videos, you'll see the Season number and episode in the title. Also notice how they uploaded like clockwork for several years. )
An example channel with this is "Annoying Orange". And here is their "YouTube show" (essentially a special type of playlist) - https://www.youtube.com/playlist?list=ELD3iEbOBdm3A (Notice the dates. This is from 2012 so it's not a new feature. Also notice if you click on one of those videos, you'll see the Season number and episode in the title. Also notice how they uploaded like clockwork for several years. )