No such thing as a DDR4/5 board.
Also not really any boards at $200 or less. There's too many expensive features on the chipsets these days to have prices that low, plus inflation adjustments and high demand.
The D15 coming with LGA1700 will depend on what production date you end up getting. If it's a newer one, then it should have it. If it's older, then it won't. Afaik, it's as simple as an email to Noctua with proof of purchase and they'll ship you one for free.
Gigabyte is the one to avoid, yeah. ASUS is at least functional, but their pricing is terrible. MSI won this generation by a long shot, especially since ASUS halo OC board, the Apex, turned out to be broken from the factory and ASUS had to cancel production prematurely. It was so bad that they stopped doing RMAs and simply gave people full refunds.