Here is the short answer: Yes, that will put you at a disadvantage when compared to the majority of candidates. If you were told that schools will not review your application (not look at your application) until they receive your DAT scores, then that poses a problem to your application cycle. You are retaking the exam in November, and as you said, schools will receive your DAT scores in December. AFTER receiving those scores, they will send out secondaries, and then interviews after receiving secondaries. Based on this, here is a rough timeline:
November - Retake the DAT
Early December - Schools review application/send out secondaries
Mid-December - You receive secondaries
Mid-December - You return secondaries
Early-mid January - Schools invite you for an interview
As you can see, this timeline is off from what it should be. You need to remember that interviewing in January doesn't necessarily mean that you will get an acceptance notice right away. Generally, the school has been interviewing applicants for the previous 4-5 months, and so they have a stockpile of qualified applicants on the list for acceptance before you.
One bright spot in this is that you MUST send schools a copy of your DAT score report. This will save you 2-3 weeks while the ADA sends out the official copy. Hopefully, that will speed up your process a bit.
And also, the benefit of sending AADSAS in July is that at least your schools will have it by December! Seriously, sending AADSAS out in December would allow the schools to get it in late January! You did the right thing by applying in July! Your only mistake was not taking the DAT soon enough. That's one of the reasons it is beneficial to take it in the spring: you can still retake it before the application cycle is in full-swing.
Good luck with everything!
