As far as I have seen, many West of the 101 properties are listed at delusional prices and always have been. That is a market unto itself.
While the area has been changing for decades the pace of change has been significantly higher over the last decade. Alot of this is housing related but not housing price growth related. Until 1999 there was very little in the way of what I would consider upper middle class executive homes to attract that demographic. Homes were either up to about 2000sq ft or larger homes were customs in Olivenhain, La Costa etc. While areas like Carmel Valley had nicer & larger homes to attract upper middle class families we did not. Now we we have tons of them and they have brought substantially higher incomes and spending power with them that was never here before.
Existing residents moving up often does not have a zero sum effect on inventory because quite often they dont sell the former home. Two properties in my hood, recently sold to move up buyers from my hood. One sold their home, the other (owns a big business)did not and now owns 3 in here. The buyers of Oxford’s home (both execs) still own their 1600 sq ft former home in fieldstone and keep it as a rental also. A house I recently sold on crest was bought by (2 physicians) buyers from Cardiff who kept that one also. Longtime residents around here recognize that there is a ton of money to be made by holding onto your former homes as rentals and others hold onto them for their kids. I know dozens of people that have held onto their former residences in the area. I think you are looking for simple “cause and effect” explanations to something that isnt quite so simple.