Idk. I've been sleeping with mine everyday for like 2 years. No problems here.

I think the existence of these effects is highly dependent on the person, especially since some kids with autism actually sleep with one every night because they can't sleep without something to calm them down. I also think that the weight of the blanket matters too. Mine is 15lbs (because it is the smallest weight offered by my blanket's manufacturer), but I can imagine something like a 20lb or 30lb blanket could cause breathing problems, for example.

But yeah, some people are fine with it and some are not. It's like eating food before bed. You're technically not supposed to do it because it can cause reflux etc., but some people don't have reflux problems even if they eat something and then doze off literally 1 minute later. (I get reflux, though, so I can't eat before bed.)

But you are 100% right that a weighted blanket can cause the problems you mention. It's just a luck of the draw if you'll get the effects or not.