Can I use Power BI Report Server on Azure VM image with SQL Enteprise? Do those images include "Software Assurance"?
"Alternatively, if you have SQL Server Enterprise with active Software Assurance, you can use your Enterprise per-core licenses to run Power BI Report Server"
No, those images do not come with software assurance, and Power BI Report Server isn't eligible for BYOL scenarios either. You may use the pre-configured image in Azure for test/dev scenarios if you'd like, but there is no support for production scenarios with PBI-RS in Azure at this time.