Hi. I have that edge plate pattern come through on a number of skis that have nothing wrong with them, in terms of skiing on them - both wider skis and narrower. Most of these are not rail high. If they are slightly rail high, they are not rail high within a half inch or cm. or so of the edges, which is all you need to have the ski behave optimally on snow for recreational skiing.
Often in machine grinding/flattening a ski, the techs will run the machine too hot (or some other mistake), and when the base cools it is no longer flat but rail high. I've had it happen a number of times, to the point where I've taken to flattening the bases myself always (topic for a different thread).
The point is, if the ski is rail high because of faulty base grinding at the factory or a shop (both common), then insisting on having it completely flat can take off too much base material unnecessarily for optimal ski performance and life of the ski. All that's really needed is that the base be flat within a cm. or so of the edges, in my experience and as explained in a number of threads on this site.
So don't be in a rush to have that base grind before checking with a true bar, and above all, testing the skis out on the slope. They will probably ski just fine.
P.S. For me, that pattern at the edges just shows through the wax without pitting the way your skis have (with the wax close to flat, for me). I'd guess that pitting was probably a "heating the wax evenly" problem, just as @cantunamunch described.