It was a different service. Mixin Safe has been reviewed by users on this forum. However, from what I understand, Mixin Safe hasn't actually been hacked. On the other hand, Mixin Messenger (which includes an integrated crypto wallet) had over a million users. My hunch is that the wallet that got hacked is linked to their custodial wallet service within Mixin Messenger.
Mixin Messenger was the part of review because many people used it in combination with Mixin Safe as part of their multisig setup, including me, this was clearly mentioned in official campaign rules.
They just forked open source Signal messenger and added centralized coin storing that was connected with cloud service.
I probably still have keys somewhere but I didn't run Messenger to see if it's even working now.
I've seen several incorrect posts by now. To be clear: Mixin lost $200M, not Mixin Safe.
Product is different, but company and owners are obviously the same.