EA rounds are kept with the going in assumption that whoever is applying in this round is absolutely sure about the school. The issue is that they have considered your profile, put in time and effort into getting you that seat and then if you back out, it just shows badly with the adcom. In case you are not sure about the school, you can still consider applying to their normal cycle.
Even if you want to back out with good reason, I would personally prefer backing out because of a genuine reason. That’s just how my logic works