Boeing (Spirit division) does make the engine cowling for the 777-200, which is what separated from the aircraft and caused the fire on the ground. Even in the case of a catastrophic failure of the engine, the cowling and all of it's parts are required by regulation to remain attached to the aircraft.
There was a previous incident a few years ago also on a Pratt-powered 777-200 where an engine failure cascaded into a much more serious cowling failure. Here's an article on that previous incident. I'm unable to find a source on whether the design changes discussed were ever implemented.
https://simpleflying.com/boeing-777-engine-cover-change/
The FAA in the past several years has had a particular focus on engine cowling components departing the aircraft and causing secondary damage, the most critical example being the 737 fan cowling that separated from the engine, impacted the fuselage, broke a window, and caused a passenger to be sucked out and killed.
https://en.wikipedia.org/wiki/Southwest_Airlines_Flight_1380