Correct me if I'm wrong, those who have already got DM and seniors, but I've never see someone get the line "We started processing Jane Doe's application on Month date, year." until after ecas already says "Decision Made".
Also, if you look on ecas they give you an explanation for what "In Process" means:
IN
PROCESS
(A decision has not been made yet.)
Application Received by Citizenship and Immigration Canada (CIC)
We have received your application and will review it in order of receipt. We will send you an acknowledgement letter.
Documentation Verified by CIC
We are reviewing your application to make sure it is complete and that no documents are missing. We will return incomplete applications for resubmission.
An Interview May be Required
We will review the application and decide if an interview is necessary. If so, we will inform you in writing of the date, time and location of the interview
Changing your status in ecas is solely up to the officer assigned to your case. If they're lazy, they may never change it to "in process", as I have experienced. And if they are maybe new, or CIC is becoming more strict with officers, they may change it to in process soon after they receive it.
I feel like there use to be a section on ecas that also said what "Application Received" means, but I'm not seeing it now... which could mean, it goes straight into "In Process".