First WP gives them out much earlier than USNA. That being said, it by no means says they want you more. It is what it is. Their admissions process is just different.
I can speak of the requirements for the Class of 2010. I am not sure if anything has changed but for that class you needed to have everything completed with the exception of 4 items:
3. BGO Interview
The way the LOA read for the class stated that you are guaranteed an appointment IF you successfully complete those four items.
From the USNA Admissions page:
The USNA uses a selection process known as "rolling admissions." As soon as all of your candidate packet forms are received, the Admissions Boards will determine your scholastic "whole person" qualification. If your record of achievement is truly outstanding, you could receive an early offer called a Letter of Assurance. This indicates our intent to extend an Offer of Appointment, provided all your remaining requirements (nomination, CFA, Blue and Gold Officer interview and medical) are successfully completed. A Letter of Assurance could be received as early as September of your senior year. Of course, final admission will depend on continued success and good standing in your high school as well as continuing to maintain your qualifications for the Naval Academy.
My Mid had everything completed with the exception of the Nomination. He received his LOA in October. He did CFA at NASS, BGO interview was late July and DoDMERB cleared in September. I do know plenty of early LOA's that never got DodMERB clearance until late in the process, and Most MOC nominations do no come through until December/January time frames.