Although I know you're in the process of just trying to make contact with some venues and coordinators, I think getting a WC will all depend on whether you have your wedding at a resort (which usually comes with some sort of wedding planner/staff) or at a non-resort venue (which I think usually requires hiring an outside WC).
Based on my own experience and some comments from other BDW brides, it seems like the WC's in the Riviera Maya/Cancun area aren't always quick to respond and take some time much to an anxious bride's dismay. Also keep in mind that the area is just beginning to enter its "high season" with the holidays approaching, so perhaps that's another reason for the delays.
Trust me, I totally understand your anxiety being a News Reporter/Producer myself. I'm used to having control of the situation and always being on top of things. *sigh* I think every bride gives up at least a little bit of that control when you opt for a destination wedding, but in the end, like all other BDW weddings, it all seems to fall beautifully into place!