I definitely believe it is possible to learn programming at the age of 61. Certainly not for everyone - some people are not the programmer-type at any age. But if the curiousity and the will are there and the brain is still working fine - yes, definitely!

I learned Rust at age 55.

But! Programming is not only about learning a language. There is this huge background of methods, practices, technologies (network/ip/socket, data formats, databases, unicode, regular expressions, xml/xsl, markup languuages), Operating Systems, procedures (CI, VC...) and so forth. This vast amount of knowledge is gained by experience over decades. The young programmer does not have the experience either, but has enough time ahead to become a senior eventually. It will be very difficult to reach a senior level when starting at 50 or 60 - there is simply not enough time to catch up. I started programming at age 16, btw.

So I would definitely let him dive into programming just to see how it goes and support him on this challenge. It will also serve mental fitness in high ages. Getting into programming at that age, with the need to make a living from it and no plan B - I consider this too risky!!