This is the second episode to be titled "Switcheroo". It has no relation to the first one.
Space Ghost mentions the guests are Howard Metzenbaum and Foster Brooks before he realizes the guests have been replaced by Moltar and Zorak. While Metzenbaum is never seen in the episode, Brooks filmed a small scene where he escaped from a planet named Rumyungyunsonson and that Metzenbaum is still there. This scene is never shown in the episode, but appears on the Volume 3 DVD, as does an alternate opening that is a reference to the Star Wars opening crawl.