IMO you're not very likely to get the answer you're looking for. In order to be truly reliable, the information needs to either come directly from the automaker (via TSB or some other document), or from someone who can show hands-on, physical evidence which proves both the root cause, and also what modifications were done. And from what I've seen over the years watching this stuff, automakers always release as little information as possible about any issue with their vehicles. And there are also very few folks around who are capable and dedicated enough to do the physical analysis which is required to identify the cause of the problem and the fix.
My personal favorite flavor of this is the Hyundai/Kia Theta debacle with their Theta II engines. They've replaced hundreds of thousands of those engines under recall/extended warranty over the past 10 years, and are still currently continuing to do so. However, even after all of these years, those automakers have never released an official cause and modification(s) for that massive problem. Yes, there was the 'engine debris' fairy tale from Hyundai early on, but that one was blown apart, when the problem continued to happen to subsequent vehicle years, long after it was first identified on the 2011 Sonata. There have been numerous theories proposed by lots of people (including the notorious 'whistleblower'), but never any confirmation from the automakers. And I doubt they ever will do so.
The most surprising thing to me is that Mazda has even admitted (in their TSBs) to the existence of defective parts, which they have done a few times in the past few years on multiple issues. Perhaps they just couldn't come up with any plausible mumbo jumbo, and were forced to actually be truthful about those situations.
I've had the same type of question you asked, many times in the past for a variety of situations. Definitive answers however have been very few and far between. Good luck with your search, but be leery of 'facts', with no associated credible source. There are more than a few people around who have no problem just blowing smoke, with no factual basis required.