That's an interesting take when you start factoring in the broader landscape. Video is no longer about just the short form, and increasingly attention is pulled away from Youtube by services like Netflix, Amazon Prime, and FB's video play.
I wonder how much video CPMs (particularly mid-roll) and the premium big brands are willing to pay plays a role in this vs something like a desire to growing engagement. If you incentivize creators to attract subscribers, and you have more direct ability to control messaging channels to subscribers as a platform, you might gain some levers in driving revenue that may not have existed or had as large an impact before. You also nurture desirable user-base behaviors.