That article indicates that isolated phytates resulted in reduced absorption of calcium, iron, and zinc, but no significant effect was found when consumed in a matrix. Furthermore, phytate-containing grains tended to contain other compounds such as fermentable fiber that increased the bioavailability of those minerals, resulting in very little effect. So if that’s the only evidence we have to go by, it doesn’t sound like oatmeal is going to prevent you from absorbing the nutrients from fruits and veggies you eat with it, nor does if have any affect on the other nutritional benefits derived from oats.