I've farmed Empyrium
since 7.3 was out and know that my server can't handle that kind of supply. Even if you take into account the rise in demand from release of raid, I can see that the ease of casual players getting a handful from WQ daily or weekly will easily outstrip the increased demand. And in the meantime before raids are released, the price will be in free fall because the demand was never that great.
Unlike Blood of Sargeras
there also isn't many uses for the mats others than Empyrium
, only cloth is semi-useful but it has long been at crap prices, with most of the demand only being on work order days, which will now be a non-issue. So every PS will just be channeled into Primal Sargerite