To my understanding the lawsuit is not about Reddit's content or copyright infringements but in more detail about using proxy farms and other measures to get Reddit content via Google's results and thus breaking the DMCA and they go against services providing the infrastructure to do so.

A bit comparable to how pressure was put onto payment providers to restrict sites with extreme adult content.

Side note: I find it super interesting in the filing https://fingfx.thomsonreuters.com/gfx/legaldocs/xmpjezjawvr/... that Google was able to provide them with the exact number of automated requests broken down by company.