It's a common belief that once people die they have no knowledge of this world.
Maybe that's true, maybe it's not.
Luke 19: 19-25 certainly suggests that people in Heaven and Hell can see each other:
19 “There was a rich man who was dressed in purple and fine linen and lived in luxury every day. 20 At his gate was laid a beggar named Lazarus, covered with sores 21 and longing to eat what fell from the rich man’s table. Even the dogs came and licked his sores.
22 “The time came when the beggar died and the angels carried him to Abraham’s side. The rich man also died and was buried. 23 In Hades, where he was in torment, he looked up and saw Abraham far away, with Lazarus by his side. 24 So he called to him, ‘Father Abraham, have pity on me and send Lazarus to dip the tip of his finger in water and cool my tongue, because I am in agony in this fire.’
25 “But Abraham replied, ‘Son, remember that in your lifetime you received your good things, while Lazarus received bad things, but now he is comforted here and you are in agony. 26 And besides all this, between us and you a great chasm has been set in place, so that those who want to go from here to you cannot, nor can anyone cross over from there to us.’
I've not heard of Randy Alcorn but a Google search found his take on this subject:
https://vimeo.com/337377047?fl=pl&fe=cm(The caption that pops up with the video is misleading, the video isn't about pets in Heaven as it suggests.)
I don't know the answer and won't until I die, but I like his statement at the very end of the video.
I also like the idea that the poor homeless vet who wasn't honored in life may have been able to see complete strangers honoring him in death.
My granddaughter is 11, there are milestones to come in her life that I hope to see:
Graduating from High School, Graduating from College, Getting married and Having children.
Based solely on family history the odds a greatly against me living long enough to witness these things.
It's comforting to think that if I don't, God may allow me to witness them from Heaven.