It depends on the country and how much was added. You can see everything that was added in each update here: Map of all Points of Interest, 3D Cities and Detailed Airports (w/ World Update #5 Nordics)
Landmarks might be there already, but just in the form of a generic office building or nothing but a flat picture on the aerial imagery. Unless they’re in a photogrammetry area which captures everything, yet still not as detailed as a handcrafted landmark.
These world updates are also the time when sat imagery is updated. The game started with a copy of old Bing map data (about 7 years old) and while Bing gets updated, the updates only trickle on to FS2020 in world updates (so far)