My business has disabled recordings and transcriptions because of legal concerns, but are reviewing those as a result of requests we get from end users perioidically (especially with Copilot using transcription in Teams meetings as a useful summary of meetings).
We've identified that you can set recordings (and their associated transcriptions) to delete automatically using the Teams Admin Center and they are stored in OneDrive.
But it appears if you have just a transcript ran, the transcript is stored in the meeting organisers exchange online under FolderPath: "/ApplicationDataRoot/93c8660e-1330-4e40-8fda-fd27f9eafe10/MeetingTranscriptCollection" - I've verified this by browsing to that location in MFCMAPI.
I've been tasked with setting a policy to delete any transcripts in those locations older than 7 days, but I cannot for the life of me work out how to accomplish it. I know labels are going to be the way to go for this, but simulations fail to pick up any results (when I know my mailbox has transcripts stored within it).