We moved an unreleased app from one developer account to another. On 18 August we renamed the old record to "Zoo Star Old"; on 31 August we removed it completely: builds expired, beta groups deleted, removed from sale, then Remove App — GET /v1/apps/{id} now returns 404.
Our new record on the other team still cannot take the name "Zoo Star": PATCH /v1/appInfoLocalizations/{id} with {"name": "Zoo Star"} returns 409 ENTITY_ERROR.ATTRIBUTE.INVALID.DUPLICATE.DIFFERENT_ACCOUNT. We tried 44 times on 18 August (after the rename), and since the deletion on 31 August every 30 minutes at first and hourly since 1 September — 199 further attempts, all 409.
The old App ID still exists on the other team and cannot be removed ("appears to be in use by the App Store"), but that identifier does not seem to be what holds the name: both teams currently have an identifier named "Zoo Star", which Apple allows.
Has anyone seen how long App Store Connect keeps a name reserved after the owning record is deleted, and whether a Developer Support case is the only way to get it released? We do not hold a trademark; both accounts are ours.