As Sikhism is its own distinct faith, and one of the largest faiths (by adherent population) in the world, this is clearly a misnomer by the New York Times. The obvious question, then, is: of what other religion does the New York Times think the Sikhs are a sect?
A quick look at how other religions are labeled (namely, Hinduism, Islam, Judaism, Buddhism, Christianity) reveals that only the Sikh category is described using the word “Sect”. Accordingly I have sent the New York Times an e-mail requesting that they remove “Sect” from the category name. The website’s editorial staff can be reached at firstname.lastname@example.org.