They never include controversial things. Back in the day WTLIB 97 came out, people were hyped about getting access to older literature without amassing a collection of paper. Even though back then the CDROM was not even half-full (180MB if I remember) and the WT was boasting their years of digitation efforts, many JW expected newer versions to contain more digitized versions as newer versions came out. They never went beyond mid-1980's.
Even later they started removing and changing things, first revisions were made, later versions started missing "replaced" books like "Live Forever" disappeared when "Knowledge" came out. People balked at it but the WT never versioned multiple editions within WTLIB.
Since the "online" version, they removed even more material, now, for no good reason things don't go back past the early 2000s.