Sentinel RBAC in the Unified portal: who has activated Unified RBAC, and how did it go?

Following the RSAC 2026 announcements last month, I have been working through the full permission picture for the Unified portal and wanted to open a discussion here given how much has shifted in a short period.

A quick framing of where things stand. The baseline is still that Azure RBAC carries across for Sentinel SIEM access when you onboard, no changes required. But there are now two significant additions in public preview: Unified RBAC for Sentinel SIEM itself (extending the Defender Unified RBAC model to cover Sentinel directly), and a new Defender-native GDAP model for non-CSP organisations managing delegated access across tenants.

The GDAP piece in particular is worth discussing carefully, because I want to be precise about what has and has not changed. The existing limitation from Microsoft's onboarding documentation, that GDAP with Azure Lighthouse is not supported for Sentinel data in the Defender portal, has not changed. What is new is a separate, Defender-portal-native GDAP mechanism announced at RSAC, which is a different thing. These are not the same capability. If you were using Entra B2B as the interim path based on earlier guidance, that guidance was correct and that path remains the generally available option today.

A few things I would genuinely like to hear from practitioners:

• For those who have activated Unified RBAC for a Sentinel workspace in the Defender portal: what did the migration from Azure RBAC roles look like in practice? Did the import function bring roles across cleanly, or did you find gaps particularly around custom roles?
• For environments using Playbook Operator, Automation Contributor, or Workbook Contributor role assignments: how are you handling the fact those three roles are not yet in Unified RBAC and still require Azure portal management? Is the dual-management posture creating operational friction?
• For MSSPs evaluating the new Defender-native GDAP model against their existing Entra B2B setup: what factors are driving the decision either way at your scale?

Writing this up as Part 3 of the migration series and the community experience here is directly useful for making sure the practitioner angle is grounded.