IIRC, there are certainly more than one reported failure on this site. That being said, I personally know of two in my area. Apparently one in just under 7k miles, and the other somewhere just under 20k miles.
I think you have to look at this in multiple dimensions:
1). The failure is statistically unlikely to happen to an owner (though statistically it appears to be a higher probability than with a CP3, etc)
2). If it does happen, depending on your circumstances, this particular failure could be extremely problematic (ie, some of us pulling livestock with GN trailers - very difficult to deal with)
3). Is FCA stepping up to the plate in supporting their customers (sure does not feel that way- not much in the way of transparency, and more than one report of FCA seeming to try and avoid responsibility by blaming the issue on "bad fuel"
4). What is the impact of this issue on the resale value of the vehicles post warranty? In other words, will this be like the "Don't buy a 2003 MB!" (back when it was Daimler-Chrysler, and quality had dropped). Will people avoid these and prefer either an '18 or a '21 or newer? I sure would if I did my research. Even if you spend the $3k to retrofit the CP3, is it possible that resale value (real world) would still be affected?
These are the reasons that I chose to work out a deal to replace my '20 with roughly 4k miles with a '21. The most important of these were items 1, 2, and 4.