I have cut and pasted the section of the Code on the transfer of an application for naturalization. The Code says you have to write and request the file to be transferred. It tells you everything that has to be in the written request. It is up to the District Director in Atlanta to agree to the transfer or not.
So, even though it appears there has been a transfer based on your AR-11, if you want to be sure, make an Infopass appointment. If the District Director in Atlanta transfered the case, the filing will remain the same. Your interview in Miami will be rescheduled if your file has been transferred by Atlanta. I am reading tea leaves if I told you your file was transferred. Only CIS knows that and you need to go in to be sure. Nothing moves fast with CIS. Miami is a very large office with millions of cases. So it could take 6 months for a new appointment.
If you want to know something sooner, again, the best place for an answer is through the Infopass appointment system. Especially, since you did not write and request a transfer like the law says.
8 CFR Sec. 335.9 Transfer of application.
(a) Request for transfer of application. An applicant who, after filing an application for naturalization, changes residence, or plans to change residence within three months, may request, in writing, that a pending application be transferred from the current Service office to the Service office having jurisdiction over the applicant's new place of residence. The request shall be submitted to the office where the application was originally filed. The request shall include the applicant's name, alien registrati on number, date of birth, complete current address including name of the county, complete address at the time of filing the application, reason for the request to transfer the application, and the date the applicant moved or intends to move to the new jurisdiction.
(b) Discretion to authorize transfer. The district director may authorize the transfer of an application for naturalization after such application has been filed. In the event that the district director does not consent to the transfer of the application, the application shall be adjudicated on its merits by the Service office retaining jurisdiction. If upon such adjudication the application is denied, the written decision pursuant to § 336.1 of this chapter shall also address the reason(s) for the Service's decision not to consent to the transfer request. (Revised 9/24/93; 58 FR 49914)