I think you're confusing induction versus synchronous reluctance permanent magnet motors with AC versus DC.

The motors Tesla uses are all AC, but you could also call them DC if you're referring to the whole motor/inverter assembly, which inputs DC from the battery.

DC motors aren't used much in EVs because the brushes require periodic maintenance and doing regenerative braking or running in reverse are both rather difficult whereas with a motor that runs off of 3-phase power, those features can be implemented in the software of the motor controller. They tend to be rather low efficiency, too. That said, there are some really powerful and cheap series wound DC motors that have been used to great effect in vehicles like the White Zombie.

Articles refer to the rear motors as DC similar to the DC motor used in the leaf. Here's an example:

https://www.motortrend.com/news/electric-cars-explained-gear...

I'm pretty sure the author of that article is just confused. The synchronous reluctance motors in the Model 3 run on AC just like an induction motor, but can be thought of as a DC motor if you consider the whole inverter/motor assembly, just like an induction motor.