The very first question I have to ask is:
Are you 100% completed with your application? Everything in the online application? Your CFA test? Your ALO interview?
The reason I ask is: Unless you are 100% complete with your application, they aren't going to look at it. Doesn't matter when the board starts reviewing packages. If yours isn't 100% complete, they aren't even going to look at it.
Now; assuming your application is complete, the answer is: The academy reviews completed packages weekly. They usually start the process of board review in the middle/end of September. That does depend on many factors. 1) How many completed applications there are; the schedule of the review board members; etc... There isn't a separate or different review board for early admissions. It's the same for everyone.
The difference with early admissions, is instead of the average applicant finding out in March/April if they received an appointment, you will find out in January one of 3 scenarios. 1) You definitely are getting an appointment; 2) You're still competitive but will have to be included with the rest of the applicants; or 3) You aren't receiving an appointment.
The only advantage an Early Admissions applicant has, based on their self reported information, is that the academy promises to not make you wait until April before at least giving you some idea if you've got a chance or not.
As for the LOA's, that is a totally different story. Because most NCAA recruited athletes go through an official signing day, which IS CONTRACTUAL, (Except for the military academies); and that signing day starts in November and continues on; (Depending on the sport); the academies want to try and convince them to come to the academy. An LOA promises the applicant that "IF THEY QUALIFY", and receive a nomination, they WILL receive an appointment. If they didn't give out ANY LOA's, most recruited athletes applying to the academy would have to wait until March/April and probably would accept other offers and sign during signing day in November/January.
Also; on some RARE occasions, LOA's are also given out to Non-IC athletes. E.g. the 4.0gpa, IB/AP student, #1 class rank, 32+ACT, etc... with the PERFECT application. But most are to help get some student athletes interested who normally won't turn down other offers waiting around until April to see if they got into the academy.
And not to diminish the meaning of a "Blue Chip" athlete; (My son was a blue chip athlete going into the academy), but it doesn't mean the same as in the real world. In the real world of college sports, a "Blue Chip" is an athlete who is guaranteed a scholarship to play sports at the school. At the academy; ALL recruited athletes are considered "Blue Chip". But at the academy, you can come in as a recruited football player and change your mind and just stay as a regular cadet and not do sports. In a real college, you'd lose your scholarship. Terms like Blue Chip and "Signing Day" (Which has not contractual meaning at the academies vs a private school) are terms and events used because it is familiar with the average high school athlete and their family; and it is easier for everyone to refer to academy athletes the same way. Don't get me wrong. Academy NCAA D1 athletics is just like every other school in it's competitiveness and demands. They follow ALL of the same NCAA rules. The difference is the athletes themselves. At the academy, the "Eligibility" standards for the athlete is higher than at a traditional school. Plus, the academies don't give out scholarships. You can be the #1 heavily drafter quarterback that air force is going after.... accept the appointment to the academy..... and after basic training say..... No, I don't want to play football. I want to be a full time cadet and concentrate on academics. You don't lose your appointment. In a traditional school; you don't play, they don't pay. (Your scholarship).