Some materials will have UV signature in their name. Those are UV dependant and will require your model to have proper UVs. But most materials use mapping generated node output and should be working fine on any model, just don't forget to apply the location, scale values, because sometimes people tend to forget to do that. Also it is highly recommended to make at least basic UV's anyways, just select sharp edges and unwrap the model, it's so easy in Blender.
Not all the materials! Some Mixed materials that you can create with Mask Generator can become too heavy for Eevee, plus, unfortunately, Eevee does not support rendering of some standard nodes. But most materials should be visible in Eevee, but they shine and have all the quality in Cycles and should render with no problems.