Field level security / permissions.

Azure DevOps - Security - Organize roles per service/section and visibility control

Allow testers with Manage Test Artifacts Permission to be able to delete test artifacts again

Visualize the rights of a user/group on all different aspects of a Team Project

Team level access

Control who is allowed to use the REST APIs

better permission management (user interface, identity picker)

Separate Test Suite Permissions - I would like to see Modify and Delete as separate permissions in TFS

Ability to link VSTS to Multiple Azure Active Directory instances for Vendor Collaboration

Allow more permission management on stakeholders