It seems the maptypes are now named like this, according to https://developer.apple.com/documentation/mapkit/mkmaptype :
case standard
A street map that shows the position of all roads and some road names.
case satellite
Satellite imagery of the area.
case hybrid
A satellite image of the area with road and road name information layered on top.
case satelliteFlyover
A satellite image of the area with flyover data where available.
case hybridFlyover
A hybrid satellite image with flyover data where available.
case mutedStandard
A street map where your data is emphasized over the underlying map details.