The Simpsons disappeared into its own massive character base. It would probably be very reinvigorated if they did had the family move, and were disciplined about NOT bringing old characters back to cameo
I've often suggested they should do an entire season set 6 or 8 years in the future, where Bart and Lisa are in high school and Homer and Marge are getting older, to explore a different slice of life's issues. Sure, they've worked in a few things that are rightly an older kid's story by trickery (Bart getting a driver's license, Lisa "smoking" via second hand, several slightly out of place romances) but there's a lot more teenage material it's not easy to cover.
Also, I just think it would be hilarious if the entire season was done that way without any warning or explanation, and then the season after they reverted to their original ages and timeline, also without any warning or explanation.