The introduction and massive expansion of new algorithms based on Machine Learning (ML) and Deep Learning (DL) processes to support knowledge and design processes is revolutionising multiple knowledge domains in recent years. Among them, research in the fields of Cultural Heritage, Design and Architecture is fueling the introduction of new methodologies of study and content creation, partly in support of existing tools and partly as a complete replacement for them, offering a new paradigmatic view of the impact of AI in these domains. Specifically, the introduction of GenAI and the construction of new content within the three domains opens new avenues in the understanding, analysis, design, and communication of both architecture and design, while highlighting limitations and risks in their unknowing use and opening up ethical questions. Human support and supervision in generative processes is still, fortunately, a foundational aspect of the processes, providing control over the results, stimulating their implementation in different areas. Through a concise review of current research in the field, the article provides an up-to-date frame of the latest global research, foreshadowing potential developments in the immediate future of XR and AI in Cultural Heritage, Design, and Architecture.