This is absolutely correct. In total, UMich will receive about 65,000 apps and roughly 40,000 of them will be submitted EA. UMich will accept about half their class, or 7,500-8,000 apps, during EA. And what that means is that majority of those 32,000+ remaining EA apps are deferred to the RD round.
Having said all that, you never really know what the readers (and computer algorithms) are looking for in an application when crafting a class.
One last thing, if you have Naviance, check to see how many apps have historically been submitted from your HS, how many have been accepted and have many have enrolled. IMO, these are important stats to UMich too.