I honestly think it was a matter of simply not having enough test drive cars on hand in various states to accommodate Touring and Pure test drives. Not to mention, no Touring or Pure trim cars existed at that time.
Back in April, they were barely getting started delivering GTs to customers.
Now, with production "back on track" as far as we can tell, they seem to be producing more cars specifically to be used as test drive vehicles. My guess is once those are spread around to the various studios, test drives will be cleared for any reservation holder.
I am very curious whether they will have the various trim levels on hand to test drive, as well. As of now, every test drive report I've seen was in a GT. I will report on Friday whether or not my test drive car was a GT or an actual Touring.