Do they really recycle the old memory chips? If you take a GPU it usually has about 8 memory chips. And its very easy to remove these chips if you have the right equipment. Heat it up for a minute or two and remove it with a suction pen. The pain will come right after.
Its very difficult and time consuming to take off the old solder and then you need to carefully apply the balls on the solder joint, you use a stencil to do this. Again this is doable however doing 8 chips will take 30-60 minutes depending on skill level. If this was reballing some GPU chip for a product worth $500 it would be worth it, but to go thru this hassle of reusing the memory chips just sounds crazy.
I have heard many times that it is better not to reball the memory, and it will work worse due to possible overheating during installation. But when repairing video cards, the masters change one memory module several times, and the video card continues to work for a year or more.