Summed Up Update sizzling armor in Gem Store
The “new” armor skins are just already available armors with flamey effects added to them. Though this is just lazy work by itself, the bigger problem is that the light version of the armor was a copy of the Tier 3 human cultural armor, which is something that is supposed to be exclusive to human characters.
Shortly after the armor was introduced, there were complaints about it and when Anet higher-ups realized what happened, they removed the skin from the store. They are working on a redesign and when it’s ready (no idea when that will be but probably at least a month or two) the new-new armor will be available for purchase. Those who already have it, when the new armor is released the skin will change to the new appearance and they can choose to keep it or get a refund.
The medium and heavy skins are also existing armors with flamey bits added on, but because they are not exclusive skins they are still available for purchase. They’re just kinda lame because the original armors weren’t that special in the first place.