Actually no, this has nothing to do with global warming or climate control (your words). It has to do with running a business. To be honest, I was surprised when Tesla extended the unlimited supercharging past 31 December and thought it was pretty generous of the company to extend it because people weren't able to get their orders in. Tesla clearly felt the need to make a change in policy and applied it.
Like you, I contacted my OA today about changing from a 90D to a 100D. He clearly articulated what I would get, what I would lose and what it would cost me (exact same as what's been reported in this thread). At the end of the day I signed a contract for a custom built car to my specifications. The fact Tesla has changed options and offerings after I signed that contract in NO way obligates them to change that contract. What they are willing to do is let me cancel that contract and write a NEW contract under current conditions without losing my deposit. That is more than fair.
The problem with making exceptions to what contracts say is that then you have a question about where the line is drawn and someone will always be unhappy. By drawing a clear line and applying it consistently, Tesla is being far more honorable and customer-centric than many other companies in the automotive industry....
At the end of the day I (and other owners) are faced with a choice -- keep what I have already ordered (and was happy with 24 hours ago) or cancel that order, apply my deposit to a new order and order under the current rule-set/price book. As someone else posted, it is a question of "is the 100 battery and an additional ~40miles of range worth the loss of free supercharging and roughly $3500 and the loss of the exact interior I had previously ordered?" For some the answer is yes, for some the answer is no but both answers are OK depending on individual circumstances.