say you were on your deathbed due to a stroke that had left you unable to communctate and unable to move the right side of you body, your able to comunicate with your loved ones through a series of thumbs up and thumbs down you can't write anything legible due to arthritis.
would the sheer frustration drive people unaware of astral projection to comunicate through dreams?
Well, I've never been on my deathbed, so I wouldn't know, but my sister-in-law lost her grandmother a few years ago, and it was a long but peaceful passing. She and her grandmother entered a sort of shamanistic trance and they both had a 'shared' experience, and in it my s.i.l. expressed that when she 'went' with her she was in contact with a host of other entities and a long time after she was left psychic, mediumistic and precognitive, which really unnerved the rest of the family. The side-effect lasted for about a year.
But the point of this story is that in those last days, the grandmother seemed to be 'half on the other side', and her 'psychic senses' were heightened. So it's possible that in that situation the person is already communicating with loved ones in the dreamstate, not so much because they are frustrated or weakened, but because they have 'direct access' to this type of communication, but the living relatives can only comprehend/receive this via dreams, when their inhibitions or 'reality filters' are down.