I thought John had a place in LA already… in addition to Hawaii.
In the Destiny Rules doc, Mick teases John about his (John's) having to make the "long" drive from Woodland Hills to the Bellagio house in Bel Air where they were recording.
I suppose John could have just been renting the Woodland Hills house, but honestly I think he is back and forth enough to LA for business and band and other reasons that he would have a place in both locations.
So I'm betting this is just an upgrade to a better neighborhood.
maybe he bought it
for his daughter……..