What I wonder is, from a libel perspective, is putting an up-front disclaimer that your association of a person with information is done without even rudimentary validation that is true information about the person it is associated with a defense against libel, or just an admission of one of the key elements of the tort?

I'd be interested to see this litigated; I'm hoping the latter, because otherwise I expect the rate of algorithmic defamation to increase to rather intolerable levels in the not-to-distant future.