That's not accurate. They said that your wvw guild would be able to be selected from your guild menu.
The issue now is that we are seeing options to select both wvw guild and wvw team from the wvw menu. But it seems that the wvw team selection is an error on their part, as it does not remember your selection when you log out and it causes issues entering wvw after you've selected a team.
The wvw team selection is what people who have not opted into a wvw guild see once the beta begins. It's not a selection we have had access to prior to betas up until now, and for most of us who have participated in these prior betas, it's not a selection we'd have ever made.