Nigeria and Tunisia have follow cars. Senegal, Montenegro and Albania have large rifts in the sky where the panorama stitching software did a poor job. Some parts of Russia had recent forest fires and are very smokey. One road in Turkey is in absurdly thick fog. The list is endless, which is why it's so fun!
When that happens, is there a wild flurry of activity in the GeoGuessr community as players race to figure out the latest patterns?
However every once in a while you'll get huge updates - new countries getting coverage, or a country with older coverage getting new camera generation coverage, etc. And yes, the community watches for these updates and very quickly they try to figure out the implications. It's a huge deal when major coverage changes.
If you want an example of this, zi8gzag (one of the best known in the community) put out a video about a major Street View update not long ago:
https://www.youtube.com/watch?v=XLETln6ZatE
The community is very tuned into Google's street view plans - see Rainbolt's video talking to the Google street view team a few weeks back:
There is a lot of "legitimate" knowledge. With just a street you have the type of road surface, its condition, the type of road markings, the bollards, and the type of soil and vegetation next to the road, as well as the presence and type of power poles next to the road, to name a few. But there is also a lot of information leakage from the way google takes streetview footage.