I originally ordered a Plaid on 9/22/2020, which was then automatically converted to Plaid+ on 2/11/2021. Because Tesla also automatically converted by account back down from Plaid+ to Plaid on 6/19/2021, I only finalized the "next steps" on MyTesla account on 6/22/2021. Based on this sequence of event, a new Tesla insider I got in touch with told me that my order has an effective order date of 6/22/2021 and it will be prioritized accordingly. I was also told not to expect my Plaid before September.
This is in stark contrast with what my other Tesla contact was telling me, namely: my order still has Sept. 2020 priority and will be matched to a VIN as soon as production matches my order details. This new piece of information basically tells me this is all incorrect, and there is no VIN matching at all, nor any concept of "priority", until the date when all steps possible to complete are indeed complete on MyTesla. That date sets the wheels in motion of VIN matching.