Keep in mind @Carrie12, unlike reservation requests, guests don't have to specify dates they want in the system. Can they they message you about certain dates? Yep, and there's nothing you can do about it. You would think that these guests would look at your calendar first before making an inquiry, but we all know how carefully guests read listings, don't we?
My supposition for Airbnb encouraging guests to make inquiries about certain dates is because so many hosts list their properties on multiple platforms and while dates on an Airbnb calendar might show as available, in fact they were booked on VRBO or Homeaway. Some hosts don't keep their calendars updated and are only reminded when they get an inquiry.
Yes, it is a hassle but I doubt Airbnb will change it's procedures. Hope you have a great vacation....keep your phone handy!