you are right they are not as visible but they are there, with a different shape. When adjusting time and/or date I can see them changing a little.
There is another main difference you can see: the splash screen doesn’t overlay the photogrammetry polygons representing trees with actual 3d trees models. It is possible the shadows in the splash screen are computed from the PG polygons and therefore looking differently.
If you look really closely around the place you can spot the PG polygons are quite raw in the splash, and leveled out and cleaned up in my shots. Given the date to get the same luminosity and shadow length, and the change in PG poly quality, this might indicate they are working on the update region as soon as 3 month earlier than release, but this is a wild guess only.