It was something I read in their documentation a while back. In their words, the system did not yet have a word processor. Whether that means no word processing at all, or no advanded printing utilities, or something else, I do not know. I just spent some time at
http://plan9.bell-labs.com/plan9/ trying to find the reference, but did not see it. It was one of the items in a short to do list. I might go through the introductory documentation again some day, so I can post that information. If I can find it again.