Some kind of Oncidium?

[Optimist]

I think it is more of an oncidium like pink bees because of the thin roots, either that, or something with miltonia in it. It can't be carpentaria, belaeria, aliceria, brassidium, because they have very thick spaghetti sized roots. The true oncidiums also have a rounder flattened egg shaped pseudo bulb.

So when it blooms, I would fortell that it will be some sort of "dancing lady" form.

Since it does have such thin roots, while they rot easily, they also need more moisture. Mine have done well in semi hydro with lava rock medium. You really have to make sure the water in the humidity tray does not go dry. If the roots go bad, they easily grow back if you adjust your care.