A rocket launch is a very violent thing to experience. If you're months away from being dead, there's a good chance the G forces during launch would be too much for your body to deal with.
For falcon 9 you don't even reach 2G until more than 60 seconds into the flight when the engines throttle back up after passing through max Q.
Acceleration graph: https://qph.fs.quoracdn.net/main-qimg-23ba4a3fe7f535430bed80... (from https://www.quora.com/What-is-the-acceleration-of-a-Falcon-9)
Old people are fragile, but a rocket launch is <3G [0], they could choose a gentle launch profile, and it's a nice constant force pushing you back into a nice padded seat.
What damage is it actually going to do in the very short term (which is all we care about in this scenario).