That's crazy, with these high-voltage platforms they'd need some BEEFY cables- copper is something like 60% or so more conductive than aluminum, so you need a thicker aluminum wire for the same current capacity. That also makes it more difficult to work with, as a thicker cable will be less flexible and have a larger minimum bend radius.
I'd be curious to see how they're designing terminations that are resistant to aluminum's significant thermal expansion, too- that's generally a huge fire risk as the wire works itself free/loosens from the termination through thermal cycling and starts sparking.