Are you sure about that? I connected my Metamask wallet to Metawin right now and transferred some Polygon (Matic) from my wallet to Metawin to test your theory. I can confirm that I was able to play slots, live casino games and every casino section that's available on Metawin.
Based on the information I have been given, a decentralized web3 casino typically doesn't collect your data such as IP address, name, and location. This means you only need to connect your wallet to start playing and access all the games without any restrictions. However, some slot providers restrict certain regions from playing their slots after collecting their IP address where they know your location, which I believe is the first point where decentralization term falls. Beside this, the KYC process is required for players under any licensed casino operation and currently only casinos with a Curaçao license support cryptocurrencies. Since slot providers like Pragmatic Games require a casino license, it means that the casino cannot be KYC free if he has slots integrated. Therefore, and in my opinion not every casino that allows connections and opening an account through MetaMask or Dapp connections can be considered a web3 casino. This is my understanding so please correct me if I'm mistaken.
What changes in KYC do you mean? As I remember, they have a Curacao license and can demand KYC documents from users but TheQuin stated that that's most likely not going to happen and that is only a formal statement.
The changes I meant here are when they started operating under a Curacao license. I had an account on Freebitco.in around 2015 if I remember well. They never mentioned the KYC process until recently, as you can see in this topic started by Mahdirakib.
FreeBitco.in is no longer a KYC free casino 
