Interesting how they refer to iPhones as “foreign devices” given that hardware is manufactured there.
I'd say it's the control of the software stack that concerns them guven what happened to Huawei.
One interesting thing about this news is that, a lot of those ban in China are spoken announcements, by a phone call or a WeChat message. They never print it out and pass through the office. Thus, everyone need to follow it but there's no proof the ban exists.