It is exciting that Dynamics NAV 2017 has an Power BI integrated feature.
As of now, Power BI has provided REST APIs and Power BI Embedded, so ideally Power BI reports can be embedded to any web application.
Regarding your question, further plans regarding the integration/implementation of Power BI Embedded throughout Dynamics NAV 2017 or other future versions like Dynamics 365, I'd say on Power BI aspect, it is ready. It all depends on the Dynamics 365 feature development plan, so you may get the answer from Dynamics 365 forum.