Producers originally considered explaining Coach's permanent absence by saying he had retired and moved away. Ultimately it was determined that Coach would be too loyal to leave his job and friends behind, and that simply revealing he passed away was a proper way to acknowledge the real life death of Nicholas Colasanto.
In developing a replacement character for Coach, producers wanted to create someone who was something of an opposite. Ultimately they determined it best to go with a younger person with a persona similar to that of Coach.
This was Woody Harrelson's first appearance as Woody Boyd. It is explained that Woody and Coach were "pen pals", not exchanging letters, but actual pens.
This has, by far, the most story time between the hook and act 1, with five months passing. No other Cheers has more than one week pass during the opening credits.
This is the first episode to acknowledge the death of Coach previous episodes before this one had various explanations for Coach's absence.