Thanks for referencing me. I have another whack at justifying my WAG (wild-ass guess)...
Holding a press conference is a key component of the tweet. Navigation updates have happened in the past without a press conference, and Tesla will continue to release them, making better energy predictions. Torque sleep, or duty cycling the motor(s), might eek out a few % efficiency improvement and increase range a bit, and these will happen over time too, but are not worthy of a press conference.
Frankly, ending range anxiety is not about adding more range - all cars, ICEs included, have a range, and drivers can get anxious when nearing it. ICE drivers mitigate that risk with the plethora of gas stations around the world, filling up quickly. The largest issue with EVs right now is two-fold -- it takes far longer to replenish charge than filling an ICE gas tank, and the charging infrastructure is in its infancy, so there are not too many places to charge. To end range anxiety and make the EV charging experience closer to the ICE fueling experience, you have to tackle two things...
- Much faster charging; and
- Many more places to charge.
Now, a press conference is aimed at a very wide audience, media, analysts, potential buyers, and us, the faithful. Announcing a partnership with a large multinational chain which has convenient sites around the world to place a Supercharger (even 1 or 2 pedestals), is certainly worthy of a press conference. If Tesla engineers have mined the enormous amount of data they have collected on the Model S battery system and concluded they can dump far more energy into the battery more quickly, thus shortening the charging experience, they can address both aspects of the charging experience with one stroke. Now that's definitely worthy of a press conference.
Further food for thought ... the Model 3 in Elon's forecast volumes could quickly overwhelm the present and planned Supercharger infrastructure without a major disruption. Potential Model 3 buyers would be most concerned about the ability to use the car like they do their ICE cars now. I'll wager this could quench demand. Connecting the dots, this disruption could be what Elon hinted was "the demand secret weapon", in the lead up to Model 3 release.