Flew is an 81 year old atheist who suddenly gets religion, and nobody thinks it has something to do with getting closer to the grave?
I suspect it's a stronger version of the type of religion discovered in foxholes during the heat of battle.
Your point is well taken.
It leads me to consider whether or not our modern / "hurry-hurry" society that fails to take time for contemplation and the peace of just listening to the crickets as dusk falls, or too busy to spend time with the kids at something other than a soccer tournament is just too tied up with the "here-and-now" to understand and appreciate the impermanence of life.
Perhaps it's only as people understand that Death is a real and perhaps near-term event do they understand and appreciate the grander scheme of things... and that our only hope is one related to a God who cares for us?
If Flew's newfound belief in God is rooted in being old and nearing death, then it would follow that Flew's atheism was rooted in the fact that he was young and unmindful of death.