They're already doing such things, and have been since the beginning. It's a standard quality monitoring and tuning of the ranking algorithm. Google even has (o

They're already doing such things, and have been since the beginning. It's a standard quality monitoring and tuning of the ranking algorithm. Google even has (outsourced) staff that continuously performs searches and gives feedback. Sites that Google doesn't deem appropriate for their search results are regularly removed both algorithmically and via manual interventions. There's no objective ranking. Every algorithm change is effectively Google's decision against someone's site. Google has been caught abusing this responsibility with preferential treatment of AMP pages, due to AMP giving preferential treatment to Google's ads. Google knows Pinterest is blatantly spamming search, so they must have a reason for keeping them.