It is possible to populate an Azure license to a User account in a Change Workflow. This can be triggered by the population of edsvaAzureOffice365Enabled by the Azure Back Sync, as long as edsvaAzureObjectID is also populated.
The Change Workflow must set edsaAzureUserUsageLocation in a Modify Requested Changes activity prior to the operation execution.
As a post-operation step, an Update activity can set the value of edsaAzureSubscribedSkus
The required value of edsaAzureSubscribedSkus can be obtained by manually licensing a single User in the Active Roles Web Interface and then copy/pasting the resulting value as a text string.