All the evidence shows that this was a relatively unusual word until the advent of text messaging on mobile phones in the late 1990s. The June 2004 addition allows the entry to be brought up to date with a first citation from a Usenet group as recent as 1998. In common with some other ICT related words, text as a verb has widened and diffused from rare, specialized contexts to near-ubiquitous everyday presence.
Technical Note: All OED entries open in a new window. All links and functionality on OED pages are disabled.