Tesla sold more electric cars than they did combined. In terms of total vehicles, they didn't sell more than any one of them.
That said, this does seem like a good move from a business perspective. They already simplified carriage construction. Single-body casting may have diminishing returns.
Because according to this only a few manufacturers have had reductions in sales Q1 2024 (Tesla being one of them) and other than the most recent quarter almost all had increases:
https://caredge.com/guides/electric-vehicle-market-share-and...
Not sure why they would be reducing production. Growth is strong across the board.