They may be limited to engine parameters only, and just get added to a file for each powerplant, attracting no attention until someone goes looking for them.
There is clearly more to this than meets the eye.
We're asked to believe that an aircraft known to be fitted with Rolls' engine health monitoring system goes AWOL, and that it doesn't occur to anyone in Derby until several days later to go and look at how long EHM reports were being received from said aircraft.
That beggars belief - if it turns out to be true, heads should roll.