This was set up in 2019, the team having some fun! Thanks for finding us.
Sounds like some PR stunt for a video game or something.
I remember 2600 doing this a few years ago. They claimed that they found a number that was "weird" which encouraged listeners to try it out. Turns out the rabbit hole was run by them :)
Or maybe just part of a game. We recently played an at-home escape room game and one of the clues was a phone number. We dialed it and it was a recording giving information about the next part of the game.