The T shaped battery architecture has its history, but I think fundamentally it doesn't make sense for a practical EV. The floor battery makes a lot more sense, and I think GM made the right choice to follow industry trends and not use the Volt architecture as their basis.
2 seaters are a niche market. GM probably won't even be able to sell enough for compliance if they made the Bolt a 2 seater.
The reason I doubt this is because there are not optimizations made to the Bolt for sensor integration. It's all tacked on the roof as other cars are done. If the Bolt was designed as a self driving platform from the start, I would have expected to see some optimizations for this.
But you are talking about first-to-market, not first viable car. Hey, I'd buy a 200mi low cost EV sports car if it were cheap. Remember the EV1 was RWD and lighter than the Corvette even when it had lead acid batteries to power it.