The threat model for a school is kids/others disrupting sessions and creepers using access to gawp at (or communicate with kids). Since the Chinese government is unlikely to feel the need to compel Zoom to do that, the fact that they have all the keys centrally stored is not a problem.
Google's threat model actually does include state level attack (And specifically by China) to steal IP or access confidential user data.
Google's threat model actually does include state level attack (And specifically by China) to steal IP or access confidential user data.