I am on these forums longer than any of you. It should go to me.
You are making some assumptions over here:
1. You are assuming that CM is correct that it goes by seniority.
2. You are assuming that it goes by original birthdate (or join date) and not by date of rebirth or reincarnation.
I was just learning yesterday the sicha about the טענה of the מלאכים at the time of מתן תורה that they deserve to receive the torah מדינא דבר מצרא. One of the תירוצים is that when the בר מצרא wants to acquire something not for need or necessity, but for additional enrichment, and the other buyer is buying in order to establish his livelihood, the rule of בר מצרא doesn't apply.
Using the same logic, priority should be given to anyone who has never before had a biz plat, and/or one who currently doesn't have a biz plat and wants to get one before 5/31.
