I don't think Richard Fontana did the analysis, in his 2012 presentation entitled "The decline of the GPL and what to do about it" [1], he does refer to an analysis of Debian packages but that was done by John Sullivan (which was prompted by and counter to two analyses showing GPL's decline which were done by Matthew Aslett)

[1] "The decline of the GPL and what to do about it" https://events.linuxfoundation.org/images/stories/pdf/lfcs20...