ok from my experience and what i read it works like this
you are given a date where the documents have to be submitted by for me it was two months later
i submitted all my documents in the first two weeks and exactly one month and 3 days later i got a passport request
so what i've read from previous years it works like this
they go through your application and decide if you are eligible or not they make sure all documents are up to date and ect ect nothing is missing, if there is missing docs then they send you the additional documents request and put your file away for a specific period of time (two weeks to one month) and when that time comes up (like they get a notification on the computer to return to your application) they re open your folder and check if all your documents have been received and if so proceed with your application, if not they close it again until the next time
so that means they check your app every two weeks or one month i'm assuming you were given 2 months to send all your docs so depending on how long it took you to submit them (one month past the date of the request for them you will probably have to wait until your final date) but if you sent them all in pretty fast, less then one month from your request date you should get some info pretty soon
get it? LOL
thats what i've read and experienced all offices are obviously different, good luck