What will happen to dated items and dated material ?

[Mihana]

It clutters the market wards equipment listing.

Did you even read my post or just go for the tl;dr version? It does not affect anything. Right now there's nothing they can do about the dated equipment, and we probably won't see any changes until ARR (2.0 or whatever you want to refer to it as.) is released. I even posted suggestions to counter cluttering up item searches. Remove the ability to list these on the wards/auction house/whatever they add in for publicly selling items for. You can list them in your personal bazaar or trade them but cannot put them up on public selling markets.

I'd rather have them re-done with proper up-to-date stats and still being with "optimal level".
That would make them useful again instead of being relic of the past.

I can definitely agree with this part. If they were updated but left with an optimal level/favored class setting they could still be useful. Though it just depends on what changes they make to them. I still use certain pieces of dated equipment for my crafting classes when leveling them up. If you're not playing a supported class you're stuck using crakows and gaiters until you can use the vintage thighboots for one example. So I use the dated thighboots (I got a pair for levels 16, 26, and 36.) up until I can.