Musk setting the record straight on the emerald mine FUD isn't why he should stop tweeting, even if it has an effect on the SP. Honestly, I'm actually glad he's debunked that one.
Musk making enemies of urbanists by crapping all over mass transit and the science of induced demand is why he should stop tweeting, as this directly goes against the mission of sustainable transport, even if it doesn't have an effect on the SP.
There are areas where induced demand has less effect, true - remote rural areas. But induced demand even happens in closer-in rural areas - especially as road infrastructure is built out towards them, they build up as exurbs of a major city, and then they get the city's traffic problems. The faster transport is, the more an urban area can sprawl, further reducing sustainability through increasing transportation energy requirements (and making it harder to get around the area for those who can't afford the fast transportation technology).
Basically, while he debunked FUD about his background, there's been a lot of FUD going around that Tesla is part of the problem because they're still making cars. While replacing ICE cars with EVs for those that are unable to eliminate car usage does improve sustainability, we do need sustainable non-car transport, and Musk's stance isn't helping. (It's still FUD even if it's true, though, because... let's face it, while Volkswagen and Toyota do make buses for some markets including their home markets, do you see either of them truly promoting mass transit? Basically, Tesla beating the ICE incumbents leaves us better off than not beating them.)