Found some details[0] on how they're doing this:

> Marriott operates a Wi-Fi monitoring system manufactured by a third party that was installed at the Gaylord Opryland. Among other features, the system includes a containment capability that, when activated, will cause the sending of de-authentication packets to Wi-Fi Internet access points that are not part of Marriott’s Wi-Fi system or authorized by Marriott and that Marriott has classified as “rogue.”

[0] https://apps.fcc.gov/edocs_public/attachmatch/DA-14-1444A1.t...