Everything up to this point regarding the Legendary Fyr'alath has been encrypted, but it seems that the first piece of datamined information may hint at one of the quest steps.
Blizzard has done a good job with encrypting anything related to the upcoming Legendary 2-Handed Axe Fyr'alath. However, it seems that one thing might have slipped through, highlighting a portion of the questline needed to acquire Fyr'alath!
These items showed up on the Patch 10.2 PTR today:
In a vacuum, these would be pretty innocuous, however, all 3 of them are named similarly and seem to reference three professions and one of them mentions " with Fyr'alath" directly. Apart from the first one having spelling errors, the second not being Binds on Pickup and all of them being Epic, it's clear these are a work-in-progress still, but they're very likely related to the Legendary questline.
These items will likely need to be crafted using a lot of expensive materials similar to the materials needed for the Evoker Legendary which are still pricy. Attuned Glowspore Grip specifically has «Glowspores» in the name, so it's likely that we'll see Zaralek Glowspores being part of the crafting cost.
In addition, it