I don't think Aramco, by buying into Tesla, would have raised the value of oil. Quite the opposite. Are you thinking people would have assumed they were buying into Tesla to bring them down? I doubt the market would have interpreted it that way.
Personally, I think the three Tesla models are such outstanding vehicles that the cat is out of the bag and there is no bringing them down. If they don't make it it would be due to colossal internal mistakes. While everyone makes mistakes, and Tesla is no exception, the fact that they have avoided the really big mistakes that would/should have caused them to fail already inspires a lot of confidence going forward.
Sure, everyone and their brother can point to some of Musk's tweets, etc. and claim they could have done it soooo much better, but look at the results today. They got the cars right and the quality is really astounding. The Model 3 has not a single recall after almost two years of production. Almost unheard of, especially for a car that is not just recycled from an earlier proven model. And production just keeps ramping. You would think TSLAQ$ would just admit they were wrong.
OK, just dreaming on that last point.