Broke down and paid for the full article from which John Harris had previously linked an extract
As we can read, the fellow was trying to cash in on on the Strontium 90 scare in the GMT, which is confirmed as the source of the problem in 6542 bezels once and for all by this period account. Note also that it says the AEC ordered the recall of these watches.
While this does not directly correlate to dial luminous, it does add further to the impression that Rolex was taking significant publicity hits and that they were on the defensive regarding radiation content in their watches during this period. That they would be extra careful going forward in monitoring their watches' radioactivity seems only logical. Ditto their reluctance to publicly acknowledge such unpleasantness...even until today.