Is the flight attendant's phone monitored by the SMS company?

No, airlines are divided into central enterprises, state-owned enterprises and private enterprises, but no matter which one, they all exist as enterprises. First, the state absolutely does not allow airlines to do so without relevant licenses. Secondly, there is no relevant equipment, which can only be used by state security organs. Finally, there is no need to monitor the life records of staff.

It's the problem of mobile phone or communication operator, the problem of mobile phone users' setting, not the problem of airlines.