Whatever the changes, hope they can in some way upgrade my 2017 X P100D and 2018 SP100D. If the 250Kw charging issue was the wiring and not battery, couldn't a shop like Rich Rebuilds change it up? I think there's going to be big business in upgrading old cars as lots of people are going to want to keep their free supercharging and just generally want to repair/upgrade their cars instead of buying new ones (because that's the greener thing to do anyway).
I wish it were so as I represent a lot of what you're describing. 19 months ago, we bought a used 2013 S85 from Tesla and would love to keep it on the road as long as possible. I will consider spending a reasonable amount of money on upgrades to expand its utility through the years. I'm excited about the prospects of upgrading the MCU and modem, and I would love a battery upgrade if one was available to enhance range, power, lower Supercharging sessions, and longevity. Keeping vehicles on the road would be the greenest route, though it might be not fit within the profitability model of most auto manufacturers.
I would love to see more 3rd party shops improving older things, but I don't know if there's a customer base to support this. Most people would want "the latest and greatest" and many people would want a warranty attached to their pricy EV.