Rivian will let preorder holders take delivery "in the next 6-8 weeks or sooner".
Downside is, you'll have to drop your preordered model for any of the available models already built and listed in the 'R1 Shop'. This means you might not get an R1T exactly how you like it and will have to settle for whatever shows up in the shop. But for the impatient, this might be worth a much quicker delivery.
Rivian recently sent out an email about the newly launched shop that can be found here:
www.rivianownersforum.com
Access to the shop is only available through an invite that Rivian has already started sending out to preorder holders via email.
Important to note is that Rivian will just give you a week to decide if to go with a model from the R1 Shop or not, according to this statement at the end of the email:
At the moment the shop lists basic vehicle configuration info and won't give you a VIN or anything specific.
Downside is, you'll have to drop your preordered model for any of the available models already built and listed in the 'R1 Shop'. This means you might not get an R1T exactly how you like it and will have to settle for whatever shows up in the shop. But for the impatient, this might be worth a much quicker delivery.
Rivian recently sent out an email about the newly launched shop that can be found here:

Introducing the R1 Shop
More 🐎:poop: In May, we reached out to some of you, via survey and Guide conversations, to see if you were interested in reconfiguring your preorder to take delivery sooner. The volume and enthusiasm of the responses told us it was a path worth exploring. We tested this approach with...
Access to the shop is only available through an invite that Rivian has already started sending out to preorder holders via email.
Important to note is that Rivian will just give you a week to decide if to go with a model from the R1 Shop or not, according to this statement at the end of the email:
At the moment the shop lists basic vehicle configuration info and won't give you a VIN or anything specific.