When do mythic and reaper dusts expire?

[Purr]

Tooltip says 2027--is that accurate for everything you get from the remnant turn in?

 

[Lacci]

What are mythic and reaper dusts ? Never seen those ingame.
Are they used to add mythic/reaper bonuses to items ?

 

[jotmon]

Item: Dust of Mythic Power
-All Dusts of Mythic Power are Bound to Account on Acquire.
-Dusts of Mythic Power will disappear from player inventories when Sterling's Remnant Rush, the event they drop from, ends on April 1st, 2027.
-Upgraded items do not lose their abilities.
-Can be applied to random generated items, standard named items, and raid items.

 

[Igognito]

I guess I can apply then also to crafted items...
Does applying them change binding?