There are a couple of similar things that I know of:

[email protected] has a bot that posts trending communities each week. Looks like it’s been broken for a couple weeks though - I just reached out to the mods to see if they can fix it.

[email protected] - This one has a bot that post some top posts from different communities every day.

Also, if you use the Connect app, it has a random button that takes you to a random community, so that’s one way to explore. Not sure if any other apps have something similar.