It entirely depends on the school. Some colleges will “defer” 80% or more of ED applicants. Since they may in the end accept 10% or less of RD applicants methinks they actually have a good idea many of the deferred kids don’t have a chance. On the other hand, Pomona says this in it’s FAQ
“We typically defer 10-15 percent of our early applicants’ candidacies. If you were deferred, it means that the Admissions Committee found strong potential in your early application and would like to consider your application again among those in the regular decision round.”
I would not recommend applying ED to one of these schools unless you are really sure it’s where you want to go. Given that a few days ago you were asking about East Coast LACs has there been a change of focus? See List of smaller colleges on East Coast with strong science/chem?