But they're engaging in simulacra. Using the actual music is akin to lifting footage out of the shows, so it's a different thing.
Last summer, DC Comics and Warner Bros. cracked down on a bunch of shows in the audio drama world, not for using their intellectual properties (Batman, Superman, etc.) but because those shows were using tracks from released soundtracks in their audio dramas.
Paramount hasn't done anything like that, it seems. Hidden Frontier aped all kinds of stuff from the GNP releases over the years for their shows, and to my knowledge (which is, admittedly, limited on this topic) they were able to get away with it.
And boy, is it ever the understatement of the decade that the Phase II guys are going to LOVE this set!