I just upgraded Safari this morning - Google Maps is now black screen ?

Something doesn't fit. Safari cannot be individually updated. Did you also upgrade your Mac's operating system? Perhaps you should try updating Google Maps. Does their web site have a download that id compatible with your current operating system?

sor-jpg

I'm still holding off upgrading Safari to 16.0 (although I've updated Monterey to 12.6), so I can't speak from personal experience, but I've seen a report or two that people have been able to regain Google Maps (and other affected websites) by turning off WebGL via Metal.

From the Safari Develop menu, click "Experimental Features" then (near the bottom of the list) uncheck "WebGL via Metal"

Good luck

srb