Tons of other squid have photophores. One of the better know surface squid that bioluminece is the small Watasenia scintillans , also commonly called the Japanese firefly squid. They are caught in great numbers in nets around costal Japan at night and the video footage makes it look like they are pulling in great nets of glowing blue goo. Really cool. Anyways, I didn't read the article, probably should, but as CarlS pointed out they don't really suspect cephs to be the cause or these glow spots. I think they're leaning more towards things like plankton or copepods or something more along those lines. Great find!