Comment 1 for bug 2019803

lp-archive itself just serves archives based on data retained by Launchpad - it doesn't itself deal with retention.

As far as I know, the OEM archives are all private, so Launchpad already retains the underlying PPA data for them indefinitely (similar to the policy for the primary Ubuntu archive). However, we don't yet have a mechanism for allowing the mirroring and re-signing mechanism to feed its modified metadata files back to Launchpad for retention. This is essentially the same issue as we have with the ESM archives, and that's on our roadmap to figure out this cycle, so hopefully we can sort that out and tackle the OEM archives at roughly the same time.