The pilot episode of Cheers introduced a regular customer and recurring character named Mrs. Littlefield, who was never seen again. It’s a common practice for characters to get cut from a TV show after the pilot. The whole point of a pilot episode is to figure out what works and what doesn’t work about a potential series before committing to making more episodes and going for a full season. Pilot episodes are becoming a thing of the past in the streaming era, but they’re an important part of the process.

https://screenrant.com/cheers-first-episode-cut-character-mrs-littlefield-factoid/