So presumably you would kindly remind them of the possibility that they won’t see their child reach adulthood when your paths cross rather than wishing them well? “I won’t say congratulations because you will be dead before he’s 20, love the name what made you choose that, how’s the wife, how’s he sleeping?”
If his death is the only reason for disapproval we can’t eliminate children experiencing loss whether it’s a parent, pet or relative. A child losing a parent at any age is crap regardless of the age of the child or the parent. Should we stop children building relationships with grandparents too because they’re going to die possibly before the child reaches adulthood?
I’ve never stated that Jon Snow is the perfect age to be having a child but he doesn’t deserve judgement and condemnation for wanting to have a child with the woman he loves just because he’s 70+.