How could Rolls Royce monitor the engines in a plane which, apparently, had no communications systems operating?
Well they probably could, retrospectively, in the case of a normal flight - my understanding is that the EHM system stores half-hourly data snapshots for transmission once an ACARS link becomes available again.
But in this case, the third-hand quote attibuted to the anonymous 777 captain
The WSJ reported that RR indicated the engines on the Malaysia 777 were running normally for 4 to 5 hours after the reported disappearance
is clearly inaccurate, albeit perhaps inadvertently.
Perhaps that's why the mods deleted it?