When I was selling wedding gowns we only ever called them "pick ups". It's an entirely modern thing (gasp!) first begun in the formal wear industry.
Here is the thing about that style: if not done in a fairly heavy bodied fabric, and worn over a petticoat or hoop, they look like crap. I've seen dozen of commercially produced dresses using this technique, worn without a petticoat, in cheap fabrics: every one of them just looked like the girl got her dress stuck in her underwear O.o Even over a petticoat, but in thin wimpy fabrics they just look like she just slept in her dress.
To look good, the fabric itself must hold some shape without any stuffing or padding inside the folds. The kind of fabrics prom dresses are typically made from will fall completely flat.