AFAIK, Tesla continues to push out s/w updates to every car that supports OTA updates, such as 2012 model S's (excludes original Roadster?) These updates only include features supported by the installed hardware.
If this sounds precarious, consider that it's generally easier and lower-cost for a manufacturer to update it's legacy base because supporting non-upgraded vehicles, should you come in for paid service, is harder. Also, if they have improvements to autopilot, they may be at greater legal risk of they didn't update.
I'd be surprised if they started excluding you (and my 2018 M3 AWD), again, for upgrades to features your car supports. It's a Tesla differentiator.