That depends on what you mean by work. Most will surely still work as cars always did but will no longer get updates to software or to maps.

As far as I can tell my Tesla S will continue to work even if Tesla and all the charging stations disappear. But the navigation system will be much less usable and many features of the entertainment system will stop working (Spotify, TuneIn).

And if you buy from a company that produces a very large volume of cars then at least in some cases third parties will step in to support the vehicles for a fee.