A quick update for anyone that is interested.
The failure to display a Google Maps satellite image is actually related to the Windows display scale setting (and probably on Linux, although I've not yet tested this). It turns out that for the above code sample to work on Windows 11, the setting needs to be 100%. Interestingly, on Windows 10, when the setting is not 100%, the satellite image is displayed, but is incorrectly scaled.
On both the Windows 10 and 11 platforms (and probably Linux) the other Google Map types (Road Map, Terrain, etc.) fail to display. As already mentioned above, I still believe that this is caused by the current lack of WEBP support in the JavaFX WebView class (satellite imagery is still being delivered using PNG tiles).
I'm in the process of updating my JavaFX bug report.
I hope the above is helpful.