the negative trusts he has say nothing about this particular service, they are about account selling, so that's irrelevant. his idea is not clear but what I understand is that he means if an account is blocked or funds frozen due to KYC (coz that's the major reason of these cases) they can help with kyc and withdraw funds.
I know but this negative trust would affect their potential clients due to their status. I know its not related, but somehow you find the service quite risky. Like my big question about how their gonna fix this up and take note that those exchanges are huge and famous one. Not sure how, but it's totally suspicious.
If it's regarding KYC its them should fixed it themselves, cause exchange will always advise that dont deal with fixer whom might turn out to be scammers. Not judging but OP should be clear on how their gonna solve issues like this.