No, I think it has to do more with money. I wonder if YouTube is still losing money, and might not even be profitable. It's hard to believe with all the revenue they post and the ads, but they do serve a lot of videos.
Alphabet can't drastically change YouTube, as its brand is so closely tied to Google in the minds of a lot of people. (I'm still surprised how many people don't realize YouTube is owned by Google/Alphabet).
Wait you say its brand is so closely tied to Google but yet don't realize YouTube is owned by Google?
Someone at Google are trying hard to turn youtube into Google Video.