This seems like an urban legend.
Why would colleges want students applying through a system they don’t intend to read applications from? If the colleges say they read these applications, they probably do - and unless you’ve heard an AO say otherwise, don’t place too much stock in hearsay.
I’m sure they screen the applications in some basic manner (a kid with a 1700 SAT would likely need a hook strong enough that the admissions office would know to expect his/her application), and then turn to the serious ones. I’m also reasonably sure that the number choosing any given school, among 14,000 applicants a year, is 4 digits at worst (and likely the lower end of that range). That would make the numbers easily manageable - these colleges will deal with 5-6x the SCEA volume when regular decision comes along.