I'm in the same boat with the group- ordered my '21 Limited on 09-24. Dealer said from the beginning that delivery would be late December or more likely early January, but I have been hoping they were being conservative and I'd see it sooner. Not seeming that way now.
Mine is also sitting in either "shipped to storage" or "awaiting vendor installed equipment" depending on which RamChat rep I get. I have a build sheet, but no Monroney sticker, and my VIN ending #506602 will not show in the payload configurator as yet.
Brutal's comment makes sense- Limited interiors are different materials than a Tradesman, etc. so it makes sense that Ram will build them in lots. It's just a bummer that seems like this batch has been sitting a while without moving and we can't tell why.
I actually started going through VIN listings at dealers with 2021's showing in transit inventory to see if I could find any near my VIN, and then I tried to pull up the Monroney and payload numbers for them. Now THAT'S boredom... I found one with a VIN at #504XXX that had a window sticker, but I also found one AFTER my VIN at about #512XXX that showed a sticker. I think the earlier VIN was a Limited but the later one was a Bighorn, if I remember right. Seems to support that builds may be in batches by trim, not just VIN sequence.
In any event, it will get here when it gets here. I'm just excited like everyone else to finally have it, and it's hard to wait. Got my Bakflip MX4 delivered yesterday, so I will mess around with that for a while I guess...