The San Luis Obispo County Airport has plans to go larger. The plans are to extend the runway so bigger planes can use it. With that comes a bigger terminal and parking area to handle more travelers.
Something to always investigate when buying a home is where the flight path is (or in this case, where the flight path will be). I checked the Master Plan here but couldn’t find anything about a proposed flight path with the new runway. It probably won’t change much from the current one, just have bigger planes.
I remember reading a Letter to the Editor in the Trib about 6 months ago from someone in the San Luis Obispo Country Club complaining about the airport noise. Someone responded to that letter with something like “you knew the airport was there when you bought your home”.
Bottom line is don’t expect the SLO Airport to go away. It’s only going to get bigger, busier, and louder!