It sounds like you all are guessing, but do the academies state anywhere what "offer extended" means? If what you said was true..."YIPPEEE!!!" But would that give me a good chance for a waiver/medical qualification?
I can tell you that I'm not guessing, that information is uploaded to DoDMERB by the academies. So from what I know, an offer is on its way to you.
As I just stated recently in another post, the waivers/medical qualifications are completely separate from the admissions. I can tell you from my days as a reviewer, each applicant was looked at the same, and the same medical standards were applied to each applicant, regardless if whether the applicant had an offer or was just in the first phase of the admissions process (much to the consternation of many applicants and parents). The wavier authorities work the same way.
If you have any doubts, feel free to call your admissions officer on Monday to confirm.