The direct answer to this question is no. Hops do not need to be figured into the water-to-malt calculus. This ratio is used to determine strike water temperature and has a real effect on mashing enzymatics and first wort gravity (important when considering really big brews). In a nutshell, malt weight and mash thickness influences wort volume and wort gravity. Wort yield into the fermenter is another story.
Pause the hop button for a moment. Wort production sets the stage for finished beer. Conversion of starch to fermentable and unfermentable carbohydrates, extract yield, and pre-boil volume are all related to what happens during mashing. Changing mash thickness and mash temperature can be used to influence wort fermentability.
Adding hops to wort in the kettle or beer in a fermenter only influences what the hops contribute. In the brewhouse, more hops will yield more bitterness and possibly more aroma. And these same hops detract from wort volume because they soak up wort and increase waste.
Wort loss is not easy to calculate in general terms because brewhouse design and hop type do not have the same effect on all brewhouses. The bottom line is that hop additions do indeed influence your batch yield as wort losses generally increase with hop addition rates. When brewing beers with high loads this loss is often anticipated so that the net batch volume is in-line with needs.
The concern that some brewers have is that a beer is sold that ends up making consumers sick. If this were to happen things would probably change very quickly.