I've always wondered if companies like Score, with several different composers working for them, would always have an existing library of ideas they were working on, partial demos recorded, etc. which hadn't been "claimed" yet, that producers could choose from if they needed something in a rush? With all the shows they worked on over the years, it would be surprising for me if every time a show needed music from them that they'd start from scratch. Aren't composers always working on stuff?
Thing is, especially by the 80's, most game show themes were taken from existing music.
Hit Man theme = "Worlds Away" by Pablo Cruise
Press Your Luck theme = "Flash" by Keith Mansfield
Blockbusters 87 theme = "Run, Don't Walk" by Richard Myhill
Hot Potato open and close = "Stop, Look and Listen" by Donna Summer, "You Make Me Feel" by Sylvester
Body Language theme = "Working Girl March" (though I would argue the Classic Concentration theme sounds more like it)
Whew!, Go, Wordplay, and Dream House are other examples shows that used existing music for their pilots and simply borrowed elements of them for the series music.