I would like to understand how we can know which user has a licence and access to use MSI in salesforce.
I would like to automatize the assigning of MSI to some specific users based on their profile and role.
License assignment is done in SFDC, depending on whether or not the MSI visualforce widget is displayed. You cannot know who is getting it from Marketo. In SFDC, you will have to create specific layouts assigned to specific profiles. Then you can list who in SFDC have been given these profiles.