Yes, this is not a new term. It's not hard to find earlier examples of the term "social media slop" to refer to endless posts on social media. A simple Google

Yes, this is not a new term. It's not hard to find earlier examples of the term "social media slop" to refer to endless posts on social media. A simple Google search for this reveals many examples of this particular term before 2022. I remember the term "slop" being used in the context of social media as a play on the idea of the "feed" giving you mass quantities of low-quality hogwash, etc.