Sure, if you stay with moderate wide gravel tires, wide aero rims like the Nextie AGX 45 makes total sense. I have those and run it either with 40 mm wide Schwalbe G-One R or even better as my road bike with 34 mm Schwalbe Pro One which then measure 36 mm on them. Perfectly adhering to the 105 % rule and really good riding and cornering.
But, if you pair them with much wider tires like e.g. 2.20 Conti RaceKings it would probably not be of any (or only miniscule) effect. Nevertheless I pondered lacing up my Nexties with Boost hubs just for shits’n giggles to throw on my Dropbar Exceed. 
In any case: I did some aerotesting and also reviewed and showed research and 3rd party testing from e.g. Swiss Side who did some nice wind tunnel tests with regard to gravel tire widths and “knobness” as effects for drag with different rims.
You can find it here: What’s faster: Drop-bar MTB vs Gravel bike? – It’s all about the tires! – Torsten Frank . : : . tfrank.de – Das Blog