Patent images we showed here back in July 2018 promised the Tesla Model Y would have a cast structure. When he went to Shanghai to announce the start of the smaller SUV program at Gigafactory 3, Elon Musk promised Tesla's most affordable SUV would have "advanced manufacturing technologies that would be revealed in the future. If we are to believe the Twitter user Nafnlaus, that future is now.

Nafnlaus means anonymous in Icelandic, so we have no way to know on which basis he has posted this on Twitter, although he seems to know what he is talking about in the discussion that follows there: