Hopefully they considered this: “Norway transport firm steps up controls after tests show Chinese-made buses can be halted remotely” https://apnews.com/article/ruter-yutong-china-norway-electric-buses-931f3dbdab3f82402da68cbcb31f856b
I would like to add the main issue is not that China would shut down busses, but that the possibility exists and the buyers not knowing.
Cybersecurity in connected buses: understanding the European regulatory framework
Tests conducted by Ruter in Norway highlighted how Over-The-Air (OTA) software updates and connectivity modules could, in theory, provide external access to vehicle systems. Such technology is being implemented in new generation buses: the new Mercedes eIntouro for instance (Daimler Buses enthusiastically stressed in late 2024 as being the “first bus manufacturer in Europe to present a bus that is compatible with over-the-air updates“).