That is somewhat correct except that EVERY application is, at some point seen by humans, even if during the "reject review" step. Applications are initially reviewed and screened, either thru policy, software, or culture of the adcom, and broadly classified in some form or another from high to low, becoming essentially the priority for evaluation in the next step. It is necessary for humans to review every application as many things such as grade trends, postbacc/SMP, life story, may alter how applicant is ultimately viewed by the committee. This broad screening will make place you in the queue for evaluation. This queue will likely take into account this priority and when submitted. But this is a dynamic process, so as new applications come in, it can push you down in priority and delay when you get thru the process
These are then assigned in some fashion to either groups or individuals for a full evaluation. Here your are classified or scored in detail and this again becomes your priority in the next step of either group review and/or interview invite. Applications that are initially screened as below metrics will be read in what I call the "reject review" step which is how I started in admissions as a undergraduate clerk when there were mounds of paper to handle. They look for any reason that this application should be fully evaluated.
I will also add that medical schools admissions simply by sheer numbers of applications, becomes a negative process. Every school must reject at least 80% of applicants pre-interview as there is a finite number of slots for interviews. This is an Olympic class event where most candidates are very good, but only a few will be awarded a "medal" in the form of an acceptance