These days , is less than an issue which people that do not work in fashion tend to believe.
Sometimes certain clients do not even bother to get it removed. I have seen a Borgdoff Goodman catalogue were moire was not even removed in some images. It was very minimal, but it was there. So it was not the case that they di not spot it. Probably they though that the remedy would have been less appealing than a bit of moiree.
Beside, most of recent cameras and digital backs rarely produce moiree. If they do, it is normally very minimal and not so time consuming to remove as some may think.
I have shot fashion with a phase p30 ( no aa filter) for 3 years and I never had moiree issue.
If I will buy a D800 a would likely get the E model.
On the eventuality that I would be shooting a stokings catalogue or ad, or some polyester clothing, it is very likely I would be doing it tethered. Normally one of the tasks that the computer boy has to perform, is to check for artifacts while we are shooting. If they spot moiree, just move the camera a little.