ok here is what advanced nutrients is doing,
there are certain chemical reactions that have a point of equilibrium, this point of equilibrium can be adjusted by various outside forces, like temp, adding buffers or catalysts, or ph of the solute(or in the case of hydroponics h2o) what advanced nutrients has done is designed a combination of nutrients that will adjust their point of equilibrium depending on the ph of your water,
now what this means is the composition of the nutes and the availability of the nutes is going to change depending on the original ph of the water, so no advanced nutrients is not lying about their product, but keep in mind you add advanced nutrients to a 3.0 ph solution or 10.0 ph solution there be some very not-cool ratios of nutritional compounds,