@MojangSupport is there a way can get old realm backups that don't appear in the backups section on the Minecraft bedrock realm

There is not at this time. No backups are stored on our servers beyond those that are also listed on the player-facing side. The backups retained are currently limited to 1/day for 1-8 days in the past, 1/week for 9-36 days, and 1/month for 37-121 days. -JL

So all the old realm backups are gone forever?