Abstract: In the post-growth era of stock optimization, China's neighborhood regeneration has shifted from development-driven redevelopment to inclusive governance. The dynamic participation of diverse stakeholders has reconstructed the representation mechanism of public interest, challenging traditional urban planning theories. Based on participatory research into cutting-edge practices in the Guangdong region, this study systematically analyzes the new characteristics of collaborative governance in the post-growth era. It identifies three distinct models: state-led co-creation, professional-led place-making, and society-community partnered co-production, illustrating the multi-scalar public interest representation mechanisms and diverse governance structures emerging within institutional gaps. Moving beyond the conventional dichotomies of development control and stakeholder gaming, this paper defines communicative public interest across three dimensions—regulatory order, local attachment, and action expectations. This reflects an evolutionary shift from benefit-sharing and joint consultation to collaborative symbiosis and value co-creation. By highlighting effective practices of Chinese collaborative governance, the paper analyzes the evolution of decision-making relations and planning responses, including the dynamic composition of the state, the changing role of planners, and the rise of new governance alliances, providing fresh insights for community planning efficacy and governance performance.