They can already add suggested videos in end screens and in the info card drawer (although the info card drawer is not used nearly as often as it could be, and YouTube doesn't necessarily do a good job of drawing attention to it).
I am not a content creator so my opinion is solely from the viewer side. I would love to hear from people who are making the videos I watch and enjoy as well since many of them are using Youtube as their sole income. IMO, you have to please both sides to a certain extent or this all won't work.