It sounds like the Google Search Relations team, aka John Mueller, Gary Illyes, Martin Splitt and others have started a podcast, in addition to the YouTube channel. The podcast was probably Gary's idea, since he is camera shy.
This podcast is named Search Off The Record and listening to the introduction, it sounds like this is going to be a lot of fun to listen to. I doubt we will hear any secrets from this but it does sound like they will be joking around a lot in this podcast.
Gary even took a shot at this site with his "Search Engine Square Table" joke.
Listen to the intro:
Google said on Twitter it will cover trending topics in SEO, Search Console features, fun stories, and more!
Sounds like a fun idea.
Forum discussion at Twitter.