If we're talking about ChipMixer, did they actually scam? Or did some government entities merely didn't spprove of their service? 
Yes, Chipmixer was an actual scam:
~snip~
Even my chips which I had in chipmixer service for which they claimed to "delete private" keys after 7 days or whatever, were seized/transfered.
and these transactions took place good 3 months ago.
It seems that you are right, whoever had vouchers or chips was left without them. I checked some old wallets older than 1 year that only contained chips from CM, and they were all emptied. Yes, it's a bit stupid that I didn't spend them, but honestly I forgot about a few $ in those old wallets. It's really strange that it wasn't all deleted, but now we at least know where even 7GB of data came from.Even my chips which I had in chipmixer service for which they claimed to "delete private" keys after 7 days or whatever, were seized/transfered.
and these transactions took place good 3 months ago.
It was still there today morning and even when the news broke here;
Plus about "aggregation of stolen money", entities could also do that through JoinMarket and through those coordinators, no?
No they can't because coinjoins are non custodial.