It looks like Google Maps is using old imagery for some reason. If you look on Google Earth, the image used appears to be from 12 Jan 2016[1]. The more recent imagery (2022 onwards) shows the new build, and you can see glimpses of it in Street View on Google Maps.
He and his family are under Secret Service protection for life, so they are not like commoners already, so it makes sense that their houses have special treatment.
On the other hand a motivated party can easily get a satellite view from Apple Maps / Google Earth or even build a 3D map using a drone (it is not a no-fly zone). So it doesn’t really contribute to VIP’s security.
[1] https://earth.google.com/web/search/%22Robin+Masters+Estate%...