Eu encontrei uma ferramenta neste site link que informa o feed RSS real de um link da loja iTunes.
Por exemplo, quando dado: link
Ele retorna: link
A iTunes Store (iTS) não hospeda nem publica feeds. Consulte aqui :
Understanding the iTunes Client and the iTunes Store.
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When you submit your podcast, you are notifying iTS that you have a podcast feed that is located in a particular location (the feed URL). If your feed is accepted, iTS simply reads your feed each day and updates the podcast directory with any new or changed information about your podcast. Note that iTS does not cache or make a copy of your feed, nor does it cache or make a copy of your episode files. For podcasts, iTS is acting in a capacity similar to a web directory.
When users find interesting podcasts in iTS, they click the Subscribe button, causing the podcast feed URL to be copied from iTS to the user's iTunes client. The iTunes client reads the podcast feed that is located at the feed URL, then downloads the media file for the podcast's most recent episode from the web server where it is hosted.