This means that Godex is probably using exchanges like Bitfinex or HitBTC for exchanging monero since they are still supporting this coin and they have decent volume.
The first two exchanges, Bitfinex and HitBTC, do not have a very good reputation on the market. I won't say anything about Binance since I haven't noticed many complaints recently. I don't think people will directly use these platforms. But since Godex uses those exchanges, if anything happens, that will happen with Godex, and they would handle it if I am not wrong.
Few days ago I was reading in bitcointalk forum about one guy who used one centralized exchanges, and he was sending monero.
After some time they didn't allow him to withdraw his coins and they asked for proof of origin for his monero coins.
This is the first time I heard something like that, but it's obviosuly happening because he posted screenshot proof.
I saw the same thread on BitcoinTalk that you are talking about. According to that guy, he actually mined them a long time ago, back in 2017 or something like that. Now, the platform is asking for proof of the source of funds. I forgot the details and I was searching for that thread again while writing this post but couldn't find it. I don't remember the exchange name as well. But I guess the exchange had some bad intentions. I don't see any other reason why they would freeze someone's XMR without any complaints from the authorities or if they cannot detect where it came from.