Generative Artificial Intelligence (GenAI) presents a paradigm shift in social media content creation due to its unique ability to enhance media creation and aid in creative tasks. Creators have already put this into practice, and AI-augmented as well as AI-generated content is prevalent across platforms. However, the creators' perspective on how GenAI impacts social media content creation and its implications for the role of humans in the creation process remains poorly understood. Through 26 in-depth interviews, we employ an exploratory lens on human-GenAI interaction and its benefits and drawbacks in content creation. The results of thematic analysis shed light on the cooperative nature of human-GenAI interaction for ideation and the varying dynamics in the creation process, where the role of human creators changes from an executing force to verifying and controlling the actual media creation performed by GenAI.