That's a strange statement and strange conclusion. What makes you think the "preorder rate is dying out"? And let's say you're right, why do you think that implies that demand for the R1 is disappearing?
We don't have all that much information about the number of preorders, but a quick look shows this:
- 11/2018 preorders opened - 0 before this date
- 10/1/2021 S-1 filed - 48,000 at this point - that's ~1,400/month over 34 months.
- 12/15/2021 71,000 at this point - huge jump due to the IPO and publicity surrounding it
- 3/1/2022 about 80,000 prior to the price increase - that's ~3,600/month since the previous number
- 3/31/2022 end of first quarter - 90,000 at this point
- 6/31/2022 end of second quarter - 98,000 at this point - about 2,500/month currently
The biggest jump was because of the IPO. The price increase (with people cancelling) had no discernible effect on the rate of preorders.
IF preorder rates have slowed, then IMO the most likely reason would be the higher prices for new preorders plus the known long wait time for delivery for new preorders. However note that a full 20% of preorders (that's about 20,000 preorders!) have been placed in the 5 months AFTER the price increase ... that tells me that there's still huge demand even at the higher price.
Rivian has just as many R1 vehicles on order as it does RDV. I suspect the consumer vehicle is going to have a higher margin and be more profitable for Rivian - the RDV is a long term play to establish and capture that market. Rivian wouldn't be building a new plant for the R2 vehicles if it were pivoting to just producing commercial vehicles.