Seems we're masking the problem- Aircraft Operators' slackness in not amending their FPLs properly.
If you can afford to run a multi million (billion?) dollar fleet of aircraft, you can make sure than somebody puts in a CHG message properly.
Certainly in this region, RPLs are almost a thing of the past.
How can a crew walk out and go, oh bugger, my ATR72 turned into a 319???
Somebody in the company knew a lot more in advance than that.
That goes for DLA messages too.