I have a case study to replace a NAS server. One of my option would be to use Azure Files.
Currently, I already have an ADFS platform in place for my 0365 access. Do you know if it's possible to use my ADFS to access a share on Azure Files ? According to the online documentation, I must use Azure AD. In the end, it could be a constraint to have to use a supplementary auth/IAM platform to access the service.
As I understand, you have on-premise AD and you are using ADFS for accessing resources in O365. You can use Azure Active Directory to access Azure files but there is no need to create additional ID to access it. Use Azure AD Connect to sync your on-premise user in Azure.