Blender is free and open source and the license prevents it from ever going closed source. So don’t worry. I think they are just pointing out that Quixel is compatible with Blender.
Ok maybe this isn’t the right place to ask but how do I create an alpha image from a 3D object to sculpt and create a 3D printable bas relief, using Blender? Like the new bas relief tool in Zbrush. Thanks