I've seen dozens of similar projects. The assumptions of the majority were to collect money from users and buy physical gold for it, of course, after deducting appropriate commissions. I do not know that any of these projects survived on the market. Most of them were obvious scams, and others were caused by legal regulations, logistic or simply low interest of users.
I think they only claiming to have those backups since they don't have any proof at all like videos when they arrange their golds or something like that. there's nothing they can prove and in this case, they are all just talking and carefully putting the bait to lure those newbies who think gold guarantee coins exist in this industry. Nevertheless, it's recommendable to stay away from this kind of project even though you are a risk-taker because this is obviously a scam unless they prove their claim that they are currently really holding those amounts of gold they are talking about.