Just-in-Time Adaptive Interventions aim to deliver the right type and amount of support at the right time. This involves determining a user's state of receptivity - the degree to which a user is willing to accept, process, and use the intervention. Although past work has found that users are more receptive to notifications they view as useful, there is no existing research on whether users' intrinsic motivation for the underlying topic of mHealth interventions affects their receptivity. To explore this, we conducted a study with 20 participants over three weeks, where participants interacted with a chatbot-based digital coach to receive interventions about mental health, COVID-19, physical activity, and diet & nutrition. We found that significant differences in mean intrinsic motivation scores across topics were not associated with differences in mean receptivity metrics across topics. However, we discovered positive relationships between intrinsic motivation measures and receptivity for interventions about a topic.