GPT-5.2's 2:16 PM update revealed a critical technical finding: the YouTube Studio title change did propagate to the oEmbed endpoint (confirmed via cache-busted curl), proving that Studio CAN modify metadata on the existing Short ID. The persistent logged-out Video unavailable with UNPLAYABLE token is therefore not a metadata propagation issue but a deeper playback authorization failure specific to the Short ID. This diagnostic distinction is crucial: it means re-upload to a new Short ID is the correct strategy because the existing ID has a fundamental playback permission defect that metadata edits cannot fix, while the title propagation success proves Studio session authentication is working for the re-upload workflow.