I'm not sure myself
It was a very realistic dream, every time I have a similar dream, it is always very realistic, like it was really happening. Maybe it was just going to recall me that we all live for the whole eternity as souls and are reborn in next upcoming incarnations and after our death, we - like it's described in esotheric books - get the life review, during which we get mental access to the thoughts of others surrounding us during our lifetime, ones that concerned our actions? Maybe this dream was telling me that we are all connected to each other because we live in many different bodies throughout the whole eternal lifetime of our soul, that we are all just the parts of The Source itself? Hard to say.
Generally, once I got an Angel cards reading which I won in an online contest and the lady who gave me the reading stated the cards claimed I have mediumship abilities - ones that allow me to connect with the other side, with ones that passed away. Once I had another lucid dream, described already by me in this thread, in which I met my spiritual guide, my deceased grandma and many other spiritual beings that were talking to me about many spiritual truths - for example - I remember it exquisitely well - they told me that "I should love myself unconditionally"
After said grandma passed away, I had a series of similar dreams, in which she shared with me many details of her life after death. Like for example, she told me that she met in heaven one guy whom she knew during her life in flesh and she was surprised to see him there because he was not a good person. I later asked my distant relatives about this man, named Jan G*** and I was told such a person indeed existed and wasn't the nicest person on Earth, to put it in a nice way. My grandma informed me also that someone in my aunt Ela's family was going to die soon - and indeed, her husband died almost exactly a year later (his funeral was held exactly on the day of the first anniversary of gran's death).
I asked her about many things, like the date of my own future death - and was told she was not allowed to know this - and if God really exists - the reply to this last question of mine was: "yes and when I passed away, His question to me was how I got there, to which I answered:" out of my own stupidity"" Indeed, my grandmother's death was caused by her neglecting her own health - she ignored her developing skin cancer.