In a few weeks, 1% of creators already using YouTube Studio will no longer see the ‘back to Classic’ button – you’ll be notified 1st & can still access Classic features you need! This won’t apply to everyone else until early next year. More info → https://yt.be/help/a7mG
One would think you’d wait until it’s feature complete to force user change. On the streaming area you don’t have the ability to add tags or set a scheduled stream as visible in advance and you’re already forcing us over there...