As has been shown, getting accepted to summer seminar or not, has absolutely no bearing on whether you receive an appointment or not. It really is that simple. Summer seminar has it's own selection criteria and motives.
Caveat: "Did you expect anything different from me"? LOL!!!
"Applying" (Whether you get accepted or not), has a definite affect on the "Human Factor". What do I mean? Simple. When you are applying to your senator or representative for a nomination, the fact that you applied for summer seminar will usually help your cause over the individual looking for a nomination who didn't apply. Now, how much it helps is difficult to say. You may be too far apart from another applicant trying for a nomination that it doesn't help you. But assuming you are competitive for a nomination, the fact that you applied to summer seminar shows determination and commitment to the academy and receiving an appointment.
The same applies when your ALO interviews you. As much people might think it shouldn't matter, applying to summer seminar will have a positive affect on how your ALO rates you.
So, even if you know that there's no way you can attend summer seminar because of Boy/Girl's state conflict or other plans in June, still apply. It's equally as important to apply than it is to attend summer seminar.
Remember; summer seminar is not for the benefit of the academy. They will barely remember you. And when they make their selection to summer seminar, most of the applicants haven't even taken their SAT/ACT's yet; and they have no other data than what is "Self Reported" by the applicant. Summer Seminar is strictly for the benefit of the applicant. Like I said, the academy has their own criteria and motives for their selections. But applying definitely means a lot to your senators, representative, and ALO. And again, whether you go to summer seminar or not, it has pretty much no say so in whether you get an appointment or not.