From all indications based on what I've read, it appears that Tesla did an investigation on fire involved vehicles and was not able to identify the root cause so their only option was to look at the conditions present prior to those fires and remove the conditions: by capping and/or reducing charge rates. Given time, there are several outcomes, the worst of which is that they may never find the root cause and will impose the restrictions indefinitely, hoping that fires will cease and not enough people will complain and they can sweep this under the rug. Let's hope that's not their intention and they are still working on a more permanent, more acceptable fix.
Mike
Mike