This is not a zoo, it's an elephant "sanctuary". None of the keepers(mahouts) have a say in what their elephants get to do or not, that responsibility usually falls on the owner of the place or the managers. This is no different from what they do for Valentines Day, Songkran (a major Thai New Year holiday), Christmas and other festivals.
So, do not blame it on the keepers/mahouts, they work hard (long hours, 7 days a week, no holidays) for very very very little pay.