Surprised we did not hear anything regarding model s or x upcoming refresh. Only about the model Y.
With Tesla busy on Semi, Roadster 2.0 and Y - plus refining the design to manufacture Model 3 in high volumes, unclear a refresh of the S or X would be a high priority.
S & X sales are doing fine now - 12 to 24 months from now, they'll start getting more competition plus Tesla needs to bring the manufacturing costs down and move toward profitability.
If there are changes to the S & X, it's likely we'll see changes to add a few features to differentiate S/X from 3/Y and compete more effectively against other long range EVs in the same price range, plus we're likely to see a redesigned battery pack, using the same batteries as the 3/Y and possibly supporting faster V3 supercharging.
Some of the biggest improvements would be in the software - which would be an OTA update to all S/X/3/Y models - continuing to improve EAP/FSD, adding screen mirroring/improved smartphone integration, improving the navigation software, …
If you're waiting to get an S/X "refresh", you could be waiting for a while.
The biggest design change will come when Tesla is getting close to FSD and they'll shift focus from drivability to keeping the driver and passengers entertained with features like rotating front seats, workspaces, videos while driving, ...