Long-standing Microsoft 365 E5 Developer tenant suddenly blocked by PolicyViolationThrottle — 1.6+ TB of existing OneDrive data now inaccessible and eDiscovery export failing

The situation

I’m the Global Administrator of a long-standing Microsoft 365 E5 Developer Program tenant that has been active for several years.

Recently, OneDrive/SharePoint access was restricted with:

PolicyViolationThrottle | PolicyViolationThrottle.htm#1033

My primary concern is data recovery, not restoring the previous storage entitlement.

What makes this unusual

• The tenant had historically operated with a much larger OneDrive storage allocation.
• I did not receive or notice an actionable warning explaining that my existing data would become subject to a significantly lower storage limit before the restriction occurred.
• Microsoft Support has already investigated the issue, including Tier 2 escalation and consultation with Microsoft engineering.
• I was directed to Microsoft Purview eDiscovery as the recovery method.

The important part is that Purview can still see the data:

~1.6+ TB of content is discoverable in the affected OneDrive sites.

However, when I attempted an eDiscovery export, the export completed, but the available package was only ~5 KB, appearing to contain reports/metadata rather than the actual files.

So I currently have this situation:

Microsoft's systems can discover hundreds of GB of my existing OneDrive data, but I have no working way to retrieve it.

What I need clarification on

1. What exact storage entitlement was applied to this tenant when the restriction was triggered?
2. Was there a backend policy/entitlement transition for existing Developer tenants?
3. What notification/warning was generated before enforcement, and through which channel?
4. Why can Purview discover ~1.6+ TB, but the eDiscovery export is not producing the actual files?
5. Is there a SharePoint/OneDrive, Developer Program, storage, policy-enforcement, or data-recovery engineering team that can assist with recovering the existing content?

I understand the current Microsoft 365 Developer Program documentation describes a 300 GB pooled tenant limit. My question is specifically about the transition/enforcement on existing tenants and recovery of data that was already stored before the restriction.

I am not asking Microsoft to restore unlimited storage. I am asking for a supported way to recover my existing data.

I can provide screenshots, eDiscovery results, export reports, and my existing Microsoft Support case details privately if needed.

Any guidance from a Microsoft engineer familiar with Developer Program storage enforcement, PolicyViolationThrottle, SharePoint/OneDrive, or eDiscovery recovery would be greatly appreciated.