YjM
Conveniently, just few days ago a contemporary aerial imagery made by Czech national survey agency was released to the public: https://lms.cuzk.cz/lms/LMS_wms_02e.html?mapfile=WMSD24.2019.PRIM03.00203&viewExtent=-852334.014,-1069470.934,-850109.569,-1066034.32&image_dir=d:/confms/lms/WMSD24/2019/PRIM
These are not yet processed to the form of ortophoto, but it's evident that nothing but the building (and the building is in a state of construction anyway) is present there. Hence I approve your changes @westnordost, and I propose to close this note as of now. Happy holidays.