No, the World's Only Surviving Tax Haven is not the US of A, according to the US-led OECD: it's poor little Trinidad&Tobago, which nearly tore itself to pieces over FATCA, eventually signed, but apparently has not yet signed up to the Common Reporting Standard.
Strong progress seen on international tax transparency - OECD
https://www.ft.com/content/94d84054-5bf0-11e7-b553-e2df1b0c3220
https://www.oxfam.org.nz/news/oxfam-disputes-opaque-oecd-failing-just-one-tax-haven-transparency
i.e. screws are being turned as we speak.Trinidad and Tobago, which previously had a rating of Non-Compliant, was unable to demonstrate progress to warrant any upgrade to its rating.
Applying the objective criteria, and taking into account the fast track reviews, Trinidad and Tobago has been identified as the only jurisdiction which has not yet made sufficient progress towards satisfactory implementation of the tax transparency standards. Discussions are continuing with Trinidad and Tobago, and progress is anticipated soon.
Strong progress seen on international tax transparency - OECD
https://www.ft.com/content/94d84054-5bf0-11e7-b553-e2df1b0c3220
https://www.oxfam.org.nz/news/oxfam-disputes-opaque-oecd-failing-just-one-tax-haven-transparency