D365 CSP Embed Licenses (Legacy → NCE): Is Admin Center Reassignment Required if Capacity Exists?

We are managing a CSP‑managed tenant that uses Dynamics 365 embedded licenses (for example, Dynamics 365 Sales Enterprise embedded, Dynamics 365 Customer Service embedded, or other service‑provisioned Dynamics entitlements).
In this tenant:

• Legacy CSP subscriptions exist for the Dynamics 365 embedded licenses
• Equivalent NCE subscriptions are ordered (or will be ordered) with equal or greater capacity
• Migration tooling is not available for these embedded Dynamics SKUs
• In Microsoft 365 Admin Center, these licenses:
  • Are not user‑assignable
  • Do not show a Legacy vs NCE distinction

Based on Microsoft Partner Center and NCE documentation, it appears that Dynamics 365 embedded licenses are service‑provisioned, and that entitlement is governed by the subscription lifecycle, not by user‑level license assignment.
We are trying to confirm the following for Dynamics 365 embedded licenses:

1. No reassignment in Microsoft 365 Admin Center is required when transitioning from Legacy CSP to NCE, as long as sufficient NCE capacity exists.
2. Entitlement will automatically continue or transition at legacy expiration or renewal based on the subscription lifecycle.
3. Partner Center (and CSP billing systems) are the authoritative source for Legacy vs NCE status, rather than the customer Admin Center UI.

Is there is an official Microsoft document that explicitly confirms this behavior for embedded licenses? Microsoft Support has unfortunately not been helpful in this process.
Thank you.