If a 100D comes out, I'm hoping Tesla will allow current X 90D owners the option of upgrading their batteries at cost ($6,000?). I would've liked the option to get a 100D, but missed out because I ordered early.
Tesla never cared about people who just bought something and missed out on something new the next day. AP hardware is a prime example. The larger batteries another.
If anything, the old 60 and 85 owners of the first days should be allowed to upgrade first. They payed the the same and got far less than everyone after them, yet they were the ones that made Tesla successful in the first days. They have the highest level of degradation at this point. I think it would only be fair if Tesla would finally 'give' them something by letting them upgrade first for a fair price (not $25k).