Sharing answers to top q's we’re seeing about the thumbnail experiment: – Custom thumbs aren't going away – 99.7% still see the creator's custom thumbnail – A lot of creators use auto-generated thumbnails, this test helps improve them for those using them: https://goo.gl/A7oDmr
As a viewer this is not something that is acceptable to me, and it seems very abusive of your creators. Also putting it on the google forum is insufficient warning, you should have prompted every person and every channel involved.