I would not recommend it unless you are planning on driving the vehicle until they crush it. You won't ever get that 5k back, but at least over 10-20 years that is a smaller loss, versus selling it after paying it off and taking a bath of the 5k, plus depreciation, plus the interest on that 5k, only to start the process over.
If it was 1-3k and you didn't have one on order, you are paying to cut in line, so whatever. May be worth it for you.
If you have one on order, not worth it.
The fact that they started at a 10k markup on a 27-33k truck and 'brought it down' to 5k due to your 'loyalty' would totally just rub me the wrong way. If they started at 5k and come down a bit, thats like 20% markup down to 10%. For me this would be at least palatable because we are in a crazy time of inflation an shortages, so almost 10% seems reasonable if you didn't do a custom order. The thing is, unlike selling a truck at MSRP, the dealership gets all the money from the markup. If they have no cars on the lot, maybe they are a bit desperate, but 5k is like the profit margin of like 3-10 cars depending at MSRP. At 10k markup, that is a 33-45% markup on the vehicle. Absolutely vile.
Again, its their right to ask this amount, but its my right to think its a bit vile.