As has been customary since at least the 991 generation came out, Porsche will really only sell its most desirable products to customers who have purchased its most expensive products in the past. You simply could not buy a 911R if you hadn't already paid up for a 918 Spyder, for example. It's the Ferrari method of proving your worth to the company or something, and it seriously rubs me the wrong way, but that's neither here nor there.
With the 992 already out, it's inevitable that the next generation of GTs will be following along on that new chassis in short order. It has been tradition that the GT3 comes first, followed by GT3 RS and then probably some form of insanely fast GT2 RS or whatever. Maybe there will be another 911R-style special edition, and the GT division is responsible for cars like the absolutely gorgeous Speedster, so whatever comes next, it'll probably be good. Do you want a new 992 GT product? You'd better get in line, and have a good relationship with your Porsche dealer to get your allocation. Or you could just buy an allocation on Bring A Trailer to benefit the Petersen Museum.
Here's what the listing says about what exactly you'd be bidding on:
As part of their annual fundraising gala, the Petersen Automotive Museum is offering the winning bidder of this auction the opportunity to secure a build slot for the soon-to-be-announced Porsche GT model. This vehicle is the product of years of testing and work by Porsche’s Weissach engineers to bring the car from the track to the streets. A teaser photo of the upcoming model is provided above.
The new GT variant will be announced in late January 2021. The build slot on auction can be used solely by the winning bidder and cannot be transferred. This no-reserve auction is for an allocation slot only, and the wining bid does not cover the cost of the vehicle, tax, or options. The proceeds from the auction will go to benefit the Petersen Museum’s annual educational programs, restoration efforts, and strategic initiatives.
Bidding on the allocation currently sits at $1300, which is significantly cheaper than buying a 918 Spyder. But there are only two days left to bid, so if you want in on this, you'd better act fast.