Well, first, there's no way that such a mandate could work. In that day, there were no standardized forms of media storage for the consumer. Disks themselves were very, very rare (and expensive) and most disk systems couldn't read disks written by a different one. Most consumer software was distributed on cassette tape or in the form of printed listings.
Second, why would this sort of mandate even be desirable?
It didn't affect my health, and not that of anyone else that I knew of back in the day.
Besides, nobody was forced to type anything in. People did it because they wanted to and enjoyed it. For many people, it was a large part of how they learned to program. If anyone had health concerns, they could easily just not type the programs in.
I would have strongly objected to the notion of regulation about this because it would have effectively makes publishing source code in printed form illegal. Aside from ethical considerations, that would have been a tremendous loss to society in general.
Second, why would this sort of mandate even be desirable?