I wouldn’t personally have a use for a white noise generator (and I wonder about battery life for something like that) in a device like this, but this reminds me of a place I once worked where they talked about piping in “pink noise” for a particular effect, so I could see a potential use for something like this in environments where different kinds of noise generation might be desirable.
Adding a motion-activated night light to such a detector would be a really nice touch, though, so I’m voting for that reason. I’d still like to see an updated Plug that incorporates a motion-sensing night light, too.