I see....
I am not sure about Pretoria specifically, but many people never get an AOR from their embassy (acknowledgment of receipt). Also, e-cas and actual letters/e-mails seem to be substantially different in many cases (timewise). So yes, an AOR letter would provide you with a file number. If they actually sent one to you or not is a good question..you also might be right and they haven't actually started processing yet. It's just impossible to tell for us...
Moreover - logging into e-cas with your file number as compared to the receipt number doesn't make any difference. You will still see the exact same information (well with the exception that you won't see the information about the sponsorhip decision if you log in under your name and file number).
If I were you I might still e-mail Pretoria and tell them that you are afraid that you might have lost your AOR/ a letter from them. Just because you don't want to miss a letter in which they are asking for additional documentation for example....
As for updates - the only one receiving e-mails/letters from now on will be you, the principal applicant. You should get an AOR, then an IA (initial assessment) and maybe letters requesting additional documentation/an interview. Which ones you will get - nobody knows
