JWs are still there. On Marriott.com home page in the Find box click the plus '+' sign in front of Hotels by Brand and the second one in the list is JW Marriott Hotels & Resorts.

Keep in mind that JWs are a subset of Marriott Hotels and Resorts. On the Hotel Directory page, select Marriott Hotels and Resorts and then click on Hawaii. You will notice that the JW Ihilani shows up.