Ed, whoever he is, is making the incorrect assumption that AOs are sitting by their computer in September awaiting something to so, so they’re welcoming applications to read. He’s also assuming that applications are read FIFO.
In general, applications are sorted by school and read together after the deadline. Just like Ed,AOs are in the field before the deadlines, talking to students at fairs and HS.
And RD applications won’t generally be read until EA/ED wraps up
There may be universities that are exceptions, but they are called exceptions for a reason.
For rolling schools, yes, earlier is better.
Now if the student has a well-crafted and complete application that has been thoroughly proofread, there is a psychological advantage to submitting it to get off their plate. But that’s unrelated to admissions advantages.