Either way, their entry into Cryptocurrency will help in adoption and introducing it to the greater masses, Tesla is the second biggest company to get in Cryptocurrency and I see this snowballing, and we shall see many more small medium, and big companies getting in the Cryptocurrency and that will push the price up, and stabilize it, it's hard to ignore when big names are into Cryptocurrency.
That will help crypto become wider when the big companies using cryptocurrency as we will see the mass adoptions in that country will grow too because people who live at that company will see the company's trust by using crypto. People will try to search for why that company uses too big money to invest in crypto. And when they can see the company's real reason, I think some of them will follow that company to invest in the crypto.
First of all the feeling of "if tesla buys some, that means it can't be too bad" is a real one, because some people who are on the fence about buying or not see these kinds of news and they end up buying as well, that is not really stupid neither because something Tesla buys could rarely be a bad investment, sure it doesn't have to go up or down constantly, it could be volatile and all, but it is surely not a scam at least, which many people are still afraid that bitcoin could be.
When you get those people to bitcoin, you get them into other crypto a lot easier as well, you can absolutely make someone buy ETH after they get into BTC, and you can definitely get them into something else when they buy ETH as well. It is a long process but people who get in like that usually do not get out that easily, only people who get in to make a quick buck leave very quickly.