This paper presents a conceptual framework examining how AI-mediated communication influences perceived brand authenticity, narrative coherence, and consumer trust in digital ecosystems. Drawing on branding theory, narrative coherence, and algorithmic mediation, the study discusses how generative AI reshapes symbolic brand communication in contexts of fragmented attention. This manuscript is shared as an Open Science preprint under Diamond Open Access principles and is intended to foster early dissemination and scholarly discussion. Future versions may incorporate empirical validation.