From personal experience and having heard reports from various guild members in various large trade guilds, it seems like the drop rates of things like rosin, tempering alloy, dreugh wax and chromium grains have all been drastically reduced. We're talking about people refining 1,000+ raw materials and getting 2 or 3 legendary refining materials... Far less than what the drop rate used to be.
I didn't see anywhere in any of the patch notes that this was being changed, nor did I see anyone else talking about this in the forums so far... I apologize if there is already a thread about this floating around somewhere.
Is this intentional or is it another bug that will get fixed in a month or six?
Either way, I'm avoiding refining my materials for now until drop rates return to more reasonable levels...