Recently, as USACO had announced, your score must be certified if you want to promote from gold to platinum. However, it means that contestants from other countries will have to stay up late (or I've misunderstood the rules). And people who are still in the gold division (like me) will be quite embarrassed! (Not complaining about USACO's problem, they are really high-quality! )
From the USACO website: "In order to promote from gold to platinum, your score must be certified."
I find it weird since from my understanding, certified contests are there to get accurate evaluations for the informatics olympiad. Why would they block access to the platinum contest unless you participate in a certified gold contest?
It is to preserve the integrity of the contests. This way the USACO Staff can monitor everyone and check if there is any cheating, e.g. code-copying. It is needed for gold to, since, if I remember correctly, EGOI finalists can be in gold. Before the EGOI-eligaible thing was in your account settings, they said "if you are eligible and in gold or plat, send us an email".