UPDATE: New timeline for transitioning Sentinel experience to Defender portal

Thanks for the update.

To be clear, when you say "managing sentinel" you are referring to the security operations?
For most MSP / security infra and multitenancy deployments the managing part are the actually resources being deployed such as the resource group, the subscription to place it in, the log analytic workspace and the RBAC access to these resources. But we also have policies in azure (activity logs, ama agent, DCR rules), cost monitoring, diagnostic loggs, resources per deployed content package being put in the resource group, logic apps, m365/azure connectors, manage identities and much much more.
So, i assume everything i mention above will remain the same (the manageing part in Azure portal) and the security operation part will move to XDR, or do we expect everything to migrate over to the XDR experience in the long run? (i believe thats not possible due to billing, resources and rbac - therefor looking for clarity and enlightenment).