As a sibling commenter suggested - to me, in order to have been scammed I need to have lost something (or, equivalently - been induced to pay more for something than I would have otherwise considered a fair price). You can certainly make the case that Redditors were "buying" entertainment with their time, so it's reasonable to describe a transaction as having taken place. I don't, however, believe that the content and comments they were consuming would be devalued if they found out that it was being submitted by a small number of people using multiple accounts. The entertainment value derived was the same.

Dishonesty is not sufficient to render something a scam - the scam-ee needs to "lose out" in some way. In this situation, I don't believe they did.