If he is actually somehow related to the casino and its team and is only here to promote the casino this way, it would probably be better for the team to properly announce the platform in the forum and they could possibly get a lot of active users from here.
I believe this website is clearly a scam website because someone already said he try the website with just 10$ and won over 2k$ but when he try to withdraw it they ask to deposit another 500$
many of these scams happen in 2018 and you can see them here
New scam schema on the forum - Free Money To Test Casinos.
Only fool will believe on that. For what we will deposit 500 dollars? LoL. I know there are legit sites who ask you to deposit but that if, you won something on their free promotion and then the deposit amount is only small like 10 to 15 dollars.
You also need to wager it but it's pretty achievable. That scam site you mentioned are not contented with the users first deposit but they want more and they want a little heavier amount this time. That was crazy. Free money on testing a casino is not new and not all of them are scam. Many scams happened in 2018 that is because cryptos are on their peak that time and then we must not forget the ICOs are also booming on that year.
And if a casino asks us to deposit more money before we can withdraw the winnings, that is very suspicious and there is a possibility that the casino will scam and not pay out the winnings. After all, no casino wants to give free money that is really free to its users because they must have terms and conditions that apply so we have to make sure of it ourselves so we don't feel cheated.
With the popularity of online casinos, many new casinos are attracting users by offering free money to try their platforms. And we have to be careful with this and maybe asking the support service about terms and conditions other than what is written on the site will be more meaningful because we can find out other things.