@lklundinTheir subsequent tweet has this interesting tidbit:
"due to FW timing. Tesla seemed to have realized no matter what they do stuff leaks through firmware so froze releases on week 40 and just backported absolute necessary stuff to limit leakage And now past the new year this must be hw they put into cars now/vsoon so cannot avoid it",
green on Twitter
Feel free to help my memory but IIRC, early 2019 saw leaks regarding (Raven) upgrades to Model S/X, which caused sales of those two models to decrease drastically with Tesla dropping prices and withdrawing all but the long range variants.
So it seems that Tesla has wisened up to the fact that they should not unintentionally Osbourne their sales via firmware upgrades that contain information about yet to come products. Because it doesn't matter whether the people looking in the firmware for clues regarding new Tesla products have no intention of denying Tesla control over when they announce these new products, what matters is whether or not the information gets out to the public.
Due to regrettable circumstances even the announcement of the 100kWh battery variant of the Model S/X was leaked this way - before Tesla had a chance to announce this milestone themselves. A technically proficient Tesla enthusiast (that doesn't need to be named now) looked in a firmware upgrade and saw information about the 100 kWh badge. Wanting to be able to prove after the official announcement that they had seen the information without actually revealing it prematurely, they used a cryptographic commitment scheme(*), but forgot to add some so-called salt, allowing others to very quickly guess the hashed '100 kWh' message - after which the genie could not be put back in the bottle.
(*) Commitment scheme - Wikipedia
In a similar vein, the father daughter team of Tesla owners and enthusiasts noticed the early buildout of superchargers and surmised the transcontinental US route would open, took a leap of faith and successfully, I seem to recall in winter did a run from New York City to California a week before the official Tesla transcontinental run in the infancy of the supercharger network.