I think it'd be great if you'd have this kind of information in your help section later on, for anxious people like me who are very wary of even having a recommendation engine at a news paper. I was actually on my way to sign up for a subscription after reading "A Renegade Trawler, Hunted for 10,000 Miles by Vigilantes" by Ian Urbina - but held back for the moment to give it more thought.
That said, I guess I could see a point in it maybe retaining users / subscribers if it's good enough. (I'd still appreciated it a lot more if this functionality could be turned off for users who request it though).
I'm not really how it would be confirmation bias. The NYT doesn't have multiple stories on the same topic with differing conclusions that it A/B tests with.
As the article states, it'll suggest articles about Hillary Clinton if you've read articles about her previously, but it doesn't say it'll only give you positive ones. There is a chance that it'll narrow people's interests (if you only read sports, for example) but that already happens anyway.
That said, I guess I could see a point in it maybe retaining users / subscribers if it's good enough. (I'd still appreciated it a lot more if this functionality could be turned off for users who request it though).