No, whitelists vs blacklists. A store blacklists some customers from entering, but in general most can enter. A store doesn't let most people put wares on its shelves, that is a whitelist. Youtube blacklists video uploads and otherwise allows everything, so it follows the same logic as customers entering a store.

No, product vs customer.

YouTube has a product they sell, advertising slots embedded in videos. YouTube's customer is the person buying the ad slot. The video and uploader are, in a tortured analogy I didn't choose about YouTube being a small store, the product that YouTube sells to their actual customer, the advertiser.

Bringing up whitelists and blacklists doesn't change that.