I highly doubt Peter Gannon would be interested in reading this thread.
First, BiaB already has this feature, you search a copyrighted song, and the style picker gives you a list of similiar styles to choose from.
Second, chord progressions are not copyright protected, so PG doesn't have to pay anything.
Third, only melody notations are subject to copyright, but a user can just do a google search and find the notes in seconds.
Fourth, if a user doesn't know how to use google, he can still use BiaB's ACW feature to figure out the chords of a song.
Fifth, BiaB is chord based, different from Guitar Pro, which is note based. BiaB serves a different purpose.