In 1991 a Lauda Air 767 broke up in mid-air when the thrust reverser on the Number 1 engine spontaneously deployed in flight. That had never happened before, has never happened since, and did not lead to a grounding of 767s.
In early August 1991 Boeing gave an alert to airlines stating that over 1,600 late model 737s, 757s, 767s, and 747s had thrust reverser systems common to that of OE-LAV. On Monday 9 September 1991 the Boeing Commercial Airplane Group asked its customers to replace a valve in the thrust reverser systems that may cause the thrust reverser to deploy in flight.
Nothing equivalent was done in the wake of TWA 800. What the NTSB did, instead, was to fiddle with the rules. And then, when the new Dreamliner could not meet the new rules, the NTSB waived the new rules.
It was merely a show. Kabuki theater. They never tried to fix a mechanical problem, because they knew that there was no mechanical problem.