Hailed for creating diverse, timely and relevant opera, activist opera company White Snake Projects (WSP) hosts the third installment of Let’s Celebrate!, an annual holiday tradition presenting brand-new operas that celebrate the diversity of the Boston area and the myriad holidays celebrated here. Mirroring the city’s demographics, Let’s Celebrate! serves up a collection of three 20-minute operas telling stories about holidays and families from various cultures around the world. With post-show panel discussions about intersectionality during the holiday season, this year’s concert embraces the traditions of Mexico’s Black Christ at Chalma, Uzbekistan’s Navruz, a national holiday celebrating the new year and new life, and Spain’s La Tomatina, a tomato throwing festival.