Well I'm not sure if they do or even have to, I think if they were subjected to AEoI or CRS they would have to have a banking license as only banks have to report. As far as I know not even e-wallets have to report, therefore its a bit far fetched to assume that money exchanges have to. I've also never been asked for a tax number, which is a standard procedure of CRS/AEoI. As far as that goes, I would have to think they do not simply share client information but this is all guessing.
I dont think any site would share their clients information and possibly cause them trouble with tax authorities if they didnt necessarily have to.
Does anyone have fact based information?