They should be able to distinguish between users who always play the same video in a loop vs. users who never watch anything twice (or anything intermediate between the two extremes) and adjust the recommendations based on that.
But maybe their recommendation engine is hyper-focused on the matrix-completion framework and doesn't use any information other than which users watched which videos.
But maybe their recommendation engine is hyper-focused on the matrix-completion framework and doesn't use any information other than which users watched which videos.