I find this idea (stores in malls) to be interesting and a very unique opportunity for Tesla. This could (possibly) help them expand their stores faster than finding, buying and dressing up old dealerships or erecting new ones.
I don't know how renting space in a mall works but the resulting increase in foot traffic to the mall might further help Tesla get their foot in the door over another tenant looking to lease the same space. The only thing I'd be concerned a bit about is servicing Tesla vehicles if the company continues to go the store-in-a-mall route. I guess the little necessary maintenance an EV needs allows Tesla to get away with this new idea where a "typical" car maker could not.