It's definitely a ploy. If they wanted to test it with just their employees, they would have put it behind their firewall.
Back in the late 90's and early 00's, I remember discovering a bunch of "internal" AOL sites. Even after posting about them on forums, AOL didn't seem to care much (unless they could be used to steal accounts).
And would have forgone the splash page.
unless they mean only for use on AOL's network, and not cross-network like with gtalk or msn chat. It's worded just awkwardly enough that I could see non-techies making that wording mistake.