Some 20 years ago, when my wife and I were shopping for new bikes, the mechanic commented, "If you both want to buy a bike, since they're the same size, it'll take me about 20 minutes to get the second one out of the bike and build it up." This wasn't K-mart, this was a bike shop. My guess is he would have spun the wheels after he put them on and aired up the tires.

Fast forward 10 years, getting a broken bike replaced 10 miles into my first tour. Lead mechanic (different shop) said, "You're on a cross country tour? Let me check the wheels before you leave." One wheel needed to be touched up 2,000+ miles into the ride, the other 5 minutes 1,000 miles later.

Based on those experiences, I'd guess the "standard of care" for wheels coming out of the box is ... zip. Just like checking grease in the bearings, or bearing pre-load, the default is to take it out and put the wheel on the bike. Presumably if the bike gets ridden a lot, during the warranty replacement of the first spoke they'll look at the rest of the spokes and touch them up (aka tension them adequately) at that point. Or up-sell the customer a fancy set of new wheels. Of course, as in my second example, some reason for concern comes up during the selling process, the sales person or a mechanic who overhears the conversation may take a second look at the machine built wheels.