The "invisible" armors were very popular (with me too!) But you never know what rewards will be like in future live events. We try to mix up rewards and base them on the difficulty it is to obtain them.
I would not go as far to say that you will never see those rewards again but you will see new rewards that equal or better those that you have come to love. Also keep in mind we can make new items with the same appearance and tailor the theme of the item toward what we are currently doing for the live events we are running.
We don't typically like to over use a certain appearance but something like "inivisible" armor pieces would be something we would likely use to add to the options of what you are able to obtain through our live events.
LINK
(Gninja) Re:Live event reward merchants to stick around for a while
