Hallo, ich habe jetzt eine Antwort vom Support bekommen: Man kann Podcasts nicht löschen, sondern sie nur archivieren. Finde ich zwar nicht die beste Lösung, aber so ist es nun mal. Hier die Aussage vom Support:
Thank you for contacting us with regards to deleting your show Komm in Balance in Apple Podcasts.
You can't delete content in Apple Podcasts Connect.
If you no longer need to manage a channel, show, or episode, you can archive it. Archiving content removes it from your Apple Podcasts Connect dashboard, Analytics, and Apple Podcasts. You can't edit content that's archived, but you can restore it to a Draft state.
See the instructions on how to archive content and how it affects your subscribers.
If you archive a channel with a subscription, all subscriptions are canceled.
Archiving an episode removes it from Apple Podcasts and from Analytics. If the episode includes subscriber audio, your subscribers lose access to it. The episode remains visible in Apple Podcasts Connect on the Episodes pane of a show page, but you can't edit it unless you restore it.