I think people misunderstand the term "supervised" - and it is used very misleadingly there as well, because by definition night time sleep when the adults are asleep as well is unsupervised. But I think people assume that if you're in the same room it's somehow fine. The use of "overnight" and "supervised" together is usually an oxymoron. The fact is when parents want to know about overnight sleeping, they mean the time when they are asleep too, and therefore unsupervised. But they are covering their arses.
It is the same with the Fisher Price product which was recalled in the US. I'm in Germany and somebody had posted in our English speaking group asking where she could buy a Rock n Play as "everyone" she knew in the States used them for their newborns to sleep in, overnight! When she was asked for a picture to clarify loads of people said it didn't look safe - it keeps the baby at a 30 degree angle, plus it has a safety harness which is a complete no-no for overnght sleeping as it's a strangulation/entanglement risk. And sure enough a few years later, deaths associated with the angle of the product and the safety harness come out, the entire product is recalled and the company has to take a load of bad publicity. The thing is it was never a bad product, it was just entirely unsuitable for overnight sleeping. However it gained cult status specifically FOR overnight sleeping, because (allegedly) babies would sleep much better in those products than in a normal cot or crib. And Fisher Price profited from that and quietly ignored the issue of the danger parents were unknowingly placing their infants in. They even marketed their product as a sleep product, with just a small line of print explaining it was for supervised sleep only.
It is very sneaky if the manufacturers of these products are hiding deaths associated with them and not issuing proper recalls or different advice. The co-sleeper that had the death associated with it (Next2me?) totally rewrote their instruction manual, added warning labels to the product, made public statements and redesigned the packaging to make the images associated with it only show totally safe uses of the different modes. That, to me, is the responsible and ethical way to respond to a consumer death (or even accident/injury) - I have a hard time trusting companies who use misleading terms like "breathable" (which means nothing) and silly oxymorons like "supervised overnight sleep".
But I have to admit, that my assumption about the sleepyhead (and similar) is that they are about as bad as cot bumpers, which would (surely?) be a step up in safety from unplanned sofa sharing.