balboa
I am not sure if I understood you correctly. If they order in which they are received determines reviews, then how exactly do you get ahead of the line in receiving interview decisions until all the applications submitted before yours are read?
Pretty much every application evaluation process goes something like this, from what I gather:
Your application review period begins, and your application is assigned to an Admissions Committee member for review
This Adcom Member, the 'First Reader' reads your application, the whole enchilada
He/she decides whether you are worthy of an interview for admission. If yes, the interview invite gets sent. Your interview gets conducted. At some point, a 2nd reader will also read over your application, and provide a similar thumbs up or thumbs down approach.
If the first Reader doesn't approve, the application is given to another adCom for review. If both the 1st and 2nd readers give a thumbs down, you get dinged. If at least one gives a thumbs up, your file goes to a committee which, using the 1st/2nd readers opinions(they could very well be part of said committee), as well as your interviewer's feedback, makes the final decision of admit/WL/ding.
As for your application getting 'jumped in line', id think the 2 main reasons would be:
1-Your first reader takes longer to read your application than someone else's does
2-Your first reader isn't sure whether you are, in his/her eyes, worthy of an interview, so your application is given to the 2nd reader to look over before deciding whether to interview you.
Again, just my experience from seeing how the R1s/EDs went down, take it for what its worth.