Are they still made? Do the materials that they are made of still exist? Or are the ones that were made by their species the only ones in existance?

Eh, the material that the Dwemer made their armour from still likely exists, but no one would be able to craft an armour like it. Most of the dwemer armour, if not all of it, is just random pieces torn of Centurions anyway. And Elven...well, I'm assuming that you mean the armour that featured in Oblivion, which is of Ayelid make. I'm not too sure what kind of material it's made of, but I assume it's still around today. But I'd assume that a few Altmer (Descendants of the Ayleids), and maybe some Bosmer (Descendants of the Ayelids that fled to Valenwood) would know how to make it.

Chances are that the material is still around, however the Dwemer used special techniques to bend the earthbones when creating their metals to help defend them against such things as rust, wear and time. The materials may still be around, but those techniques are probably lost with time save for through Yagrum...

There was elven in Daggerfall too, if I'm not mistaken. Like Orcish armour, I would say it's just armour made by Altmer.
Though yes, the elven armour in Oblivion seems to be of Ayleid design, or just made to look like it were.

If bonemold armour were to be sold outside of Morrowind, do you think they would call it "Dark Elven" then?

If bonemold was sold outside Morrowind: chitin and netch leather probably would be, too. In which case, they would collectivelly be called "Dark Elven" armors.