Used to believe that Polynesian luaus were connected to false religion and that pinatas also had connections but the WTS back tracked on that. Pinata September 22, 2003 Awake, page 22. We found that for many people in Mexico, the piñata has lost its religious significance and is considered by most to be just harmless fun. In fact, piñatas are used in Mexico on many festive occasions, not just for the posadas or for birthdays...When considering whether to include a piñata at a social gathering, Christians should be sensitive to the consciences of others. (1 Corinthians 10:31-33) A main concern is, not what the practice meant hundreds of years ago, but how it is viewed today in your area. Understandably, opinions may vary from one place to another. Hence, it is wise to avoid turning such matters into big issues.
Luaus As noted there in our footnote on page 24, while the luau may at one time have had a connection with false religious practices, the word now has simply come to refer to a Hawaiian banquet. A specific gathering to which the word "luau" is applied may or may not be appropriate for a Christian to attend. As in all aspects of life, Christians should make decisions that will leave them with a clear conscience before Jehovah God. (January 8, 2000, issue of "Awake!" pages 26-7.)
Kauai Luau Celebrations and Feasts
A Kauai luau is a party or celebration with Hawaiian music, dancing, food and fun.
Non jw source: Traditionally luaus were held as a thank you to the gods to celebrate a battle victory, the birth of child or a safe return from a long voyage. As a religious ceremony a luau consisted of elaborate rituals which needed much preparation.
https://www.jehovahs-witness.com/topic/133780/comments-you-will-hear-5-6-07-wt-review-resist-demons