Incorporating the views of residents and stakeholders in the enhancement of urban environments is widely considered essential. However, traditional participation methods have struggled to involve laypeople in providing clear and implementable design inputs. This barrier is being overcome through the use of visual creative AI tools, which enables those without formal design training to visually articulate changes, for example in streetscapes and squares. In particular, the UrbanistAI tool quickly generates diverse visualizations based on user descriptions, facilitating more effective collaborative discussions and more refined design proposals. In this paper, we explore how this technology contributes to participatory planning and e-participation practices, and address a variety of challenges it faces. We also evaluate its value in the light of recent scholarly viewpoints on the role of visualizations in urban development. Additionally, we examine various case studies using UrbanistAI, highlighting the differential impacts of this pioneering commercial tool in real-world applications across different global contexts.