While I was building it I did notice it had become harder to find a poscasts RSS feed but they definitely all still used it. I suspect it is used more as a business to business/platform to platform transport these days.
Certainly beats building thirty API integrations for people who want to roll their own syndication for their podcast.
Or use the API: https://www.listennotes.com/api/
How is the audience feedback so far?
June, 2018: https://www.producthunt.com/posts/listen-notes-3-0
Dec, 2017: https://news.ycombinator.com/item?id=15825900
But one comment that I heard again and again is: It's meaningless to build a podcast search engine, because Google and Apple can easily build something similar :)
As the episodes are syndicated it seems reasonable to "rebroadcast" the episode on your site, but the terms and conditions for many podcasts (example 99 Percent Invisible) seem to suggest that is breaching their usage rights.
Have you looked into this at all and did you find similar issues?