Properly-built wheels can be treated normally right away. If they are going to untrue themselves, they might as well do so right away so you can fix it as soon as possible.

I build most of my own wheels these days, but when I get a wheel built by a machine I always check it out in a truing stand before I ride it, and in most cases I stress-relieve it and increase the tension. I have seen machine-built wheels with fairly loose spokes.