I just means that someone "touched" your case. No one can tell you why. Some told you to move forward with your process there in UAE but I will give you some information that will help you begin with links.
Don't do anything in advance until the case is ready at embassy and the embassy sends you an email to the petitioner to follow these steps for Scheduling interview, Medical exam, police clearance etc.
I have not been able to find much on AD but here is what I have https://ais.usvisa-info.com/en-AE/niv. You should go to your sub-forum website here http://www.visajourney.com/forums/forum/97-middle-east-and-north-africa/ and here is a recent thread for some who are processing a K-1 and their recent experience (see below). Also, more info here from your portal http://www.visajourney.com/consulates/index.php?ctry=United
https://ais.usvisa-info.com/en-ae/niv
https://ais.usvisa-info.com/en-ae/niv/information/niv
http://www.visajourney.com/consulates/index.php?ctry=United Arab Emirates&cty=Abu Dhabi
Cris.R got a reaction from Miosotty M in RFE - Petitioner's Court Records
Cris.R got a reaction from MeghanK in RFE - Petitioner's Court Records
Cris.R got a reaction from TandSarahJane in RFE - Petitioner's Court Records