I believe they mean, that the textures you see on the screenshots made in 3D StudioMax are the same textures, you will see later in FSX/P3D
3dmax and gmax are basically the same thing by the same company (Gmax is actually 3d max 5) and they are not for making textures you make 3d shapes with it for textures you use Photoshop ,paint shop pro etc and even real photo images,.. the airplanes won't be better just because they were made in 3dmax instead of Gmax or FFDS
what they mean its that they are using large&high resolution drawings/photos in dds for more realism, maybe 2048x2048 dtx dds 5 and rendered is and option that as removed from Gmax beause it wont be need it to make and airplane,... its for Pictures and movie animation the rendering , so the guy use the normal textures but he grab the images using the filters and trick of 3d max so it would look realistic only for pictures and video animations but NOT for FSX,...is useless
Alex