I think this is in reaction to the confusion over Model 3 being the "next version" of the Model S. People might be holding off on buying the S because they think that the 3 is better.
When asked why he named it Model 3 in that thread, his response was: "Because I was a dumb idiot and didn't realize at the time that it would cause confusion".
https://twitter.com/elonmusk/status/845278449811939328.
When asked why he named it Model 3 in that thread, his response was: "Because I was a dumb idiot and didn't realize at the time that it would cause confusion".
This mistake seems to have stuck with him -- he made a joke about it two months later when talking about naming his boring machines: https://twitter.com/elonmusk/status/860378029515718660