That's not early, especially this year, when some schools are already reporting completed applications running well ahead of last year. Apparently, a lot of people were sitting around with nothing to do in April and May, and applications in the first few days that AMCAS opened were 50% higher than last year.
That has definitely leveled off, but, other than people waiting for delayed MCAT scores (and they've been told by a lot of schools to apply without them), if anything, applications are being submitted earlier than prior years, not later. Submitting in October this year will probably be the same as doing so in any other year.