I concur the circumstances of its launch were certainly shady, but in my opinion it's legit. It's definitely a well designed and coded dice site, so if it is a con it's a long con. Since the site is brand-new there might be some issues here and there, But I'd be very surprised if someone went through all the trouble to code up a this dice site just to run away with your coins.
Plus here's an invite link where you can earn rewards from each of your invited players:
https://letsdice.com/?invite_info=2