It may be that, but from a "in character" point of view if you will, it might be that they were afraid of meeting more children like whaziz' face, and having Cassie be reminded of her terrible atrocities. Maybe they did but it never turned up anything truly worthwhile so they didn't mention it in the books, or maybe they just figured the Chee were a good enough source of information and didn't want to rely on it. There's also the whole having to break into AOL--erm WAA's offices to figure out if possible recruits were controllers or not.
K.A. not liking the internet does seem the more practical answer though, I've never really thought about how she might feel about the net actually. I know the guy who writes Redwall aparently hates computers for example, so who knows.