Moss is a hardcore survivor, having existed for 350(+?) million years with 12,000+ species it's got a few tricks up its sleeve. There are some species that are difficult to maintain, but the kind found in those bricks is no doubt easily cultivated on a wide scale. While I've never used it myself I wouldn't be at all surprised if it started coming back to life. I made a moss terrarium a while back and some of the info on them said mosses can spring back from extended periods of drought with relative ease. But despite their survivability don't expect too much, moss grows very slowly, my terrarium is almost a year old and has barely increased in size from the original transplants.