One can but wonder how this affects Jet* operation of the Dreamliner in these circumstances .
The IFSD rate for ETOPS is tracked at both the fleet level and the operator level - the operator level stuff being done by the local regulatory authority. Fleet level is pretty strict (although I recall a case where the engine manufacture petitioned to have one operator excluded from the fleet rate because the operator wasn't properly maintaining their engines and pretty much everyone who was paying attention knew it). Operator level stuff is more flexible - someone with a small fleet could go over the ETOPS limit due to a single fluke shutdown - often it includes agreements that if there is an IFSD the operator will demonstrate they've taken corrective action to insure they don't have another (which can get tricky if you can't figure out what caused the shutdown, which occasionally happens).
In addition, the 787 (also the A350) were certified for "early ETOPS" - basically more testing is done during the certification phase to demonstrate the ETOPS capability at EIS. This was originally done for the 777 (I was involved at the time, and we literally had to invent it as we went). Early ETOPS simplifies the ETOPS approval process for the individual operators, although they still need to present a plan acceptable to the local authorities before they can begin ETOPS operations.
BTW, the A330 engines were NOT identical to the 767 - they were higher thrust derivatives of the 767 engines.