In the early hours of Tuesday morning, Elon Musk revealed that the much hoped-for updates to Tesla's Model S sedan and Model X SUV are not in fact going to happen. Replying to a fan on Twitter, Musk told him that there are no changes planned to either vehicle beyond the minor tweaks that Tesla implements every so often.

There is no “refreshed” Model X or Model S coming, only a series of minor ongoing changes. Most significant change in past few years was to use high efficiency Model 3 rear drive unit as S/X front drive unit. That went into production 3 months ago. — Elon Musk (@elonmusk) July 9, 2019

For months, the Tesla fan community has been speculating that a radical new interior—perhaps similar to the minimalist Model 3 —was planned for the Model S, which first launched in 2012. But Musk specifically disabused his interlocutor of this notion as well. As Musk noted, Tesla recently switched the front motors of the Models S and X over to the newer, more efficient electric motor used to drive the rear wheels of the cheaper Model 3. Musk has also previously insisted that there are no plans at Tesla to switch the Models S and X to the lithium-ion battery cells used by the newer Model 3.

It's standard practice in the auto industry to give a vehicle a mid-life refresh, usually after a model has been on sale for four years. Indeed, Tesla itself is no stranger to this. In 2016—four years after the Model S went on sale—the car got a front-end restyle, new headlights, and a number of interior changes. But Musk's tweets should serve as notice not to expect any such redesign of the Model X, which is now approaching the four-year mark.

It's possible this news will actually be positive for Tesla. Sales of the high-margin Models S and X have been rapidly declining of late—Electrek describes them as "crashing." In Q2 2018, the company delivered 22,319 Models S and X; for the same three months of 2019 it only delivered 17,650, after extremely heavy discounts. Many potential customers may have been holding off a purchase, waiting for significantly updated Ses and Xes; if so this news may result in an uptick of sales of these more profitable vehicles for the company.

However, another possibility is that the long-in-the-tooth Model S may soon be retired altogether. The proposed Model Y crossover derivative of the Model 3 sedan will require a production line upon which to build it at Tesla's factory in Fremont, California, and there is growing speculation that the Model S will donate its production line to this effort.