Paid product placement is something you yourself put in the video. The Company will approach you (or vise versa) and make a deal regardless of how many YouTube Red viewers you have, you will be paid the amount you and the company agree upon as the only person who can disclose how many YouTube Red viewers you have to a 3rd party is you (or anyone that has access to your account).
If you have YouTube Red the only ads that will be affected are the ones that set BY Google. As in the ads you see before the video even begins, in the side bar, they are usually highlighted in yellow in the timebar of the video if it is inserted.
If you have any other questions feel free to ask!