You will be allocated a time to disembark by Azamara - for an 0900 shuttle that is usually around 0815. You will have a luggage tag that aligns to that departure/bus. They do not ask shuttle guests to meet in a given area onboard, rather they expect you to disembark on time and make your own way to the bus, collecting your luggage, clearing any customs and taking your case to the bus. Porters may or may not be available to assist you.
Insight - once off the ship you will find very few if any shipboard staff there to help, there will be a shorex person looking out for the tour people but they will not get involved with the shuttle which is run ex Guest Relations (know this from experience)
Tip - do not expect the shuttle to depart at 0900. The ground based staff focus on ensuring the correct number are on the bus. So if someone is tardy leaving the ship (or worst case decide to make their own way to the airport but do not tell anyone you will sit and wait and wait...)
Personally its quite a lottery and self organised taxi is usually better. Of course if you have air with Azamara and are on an included transfer that is very different.