Nothing, but GES and The URO Foundation *need* URO to reach <>$300 value in order for the concept to work and they could do that by, not posting web 'news' announcements which are meaningless, but by posting copies of actual contractual evidence and the paperwork they would have to have for the shipment transit.
As I said, people who scoff at the idea of URO=1tonne of UREA, on the basis that they can't wrap their heads around commodities trading, are just ignorant about the components of how transactions would work for the businesses involved who are actually shipping physical goods and who would not at all be 'giving away' UREA at sub-market prices, as long as the coin value floor can rise to meet the required price.
That is why GES need to come up with the proof of their side of the deal actually having substance.
Their 'press' announcements given on the website and twitter are simply not acceptable proof for the market.