Found this nugget at the very bottom of the press release page explaining the new program name in detail...
https://news.alaskaair.com/loyalty/i...atmos-rewards/
The Atmos Rewards name is designed to inspire wonder. It’s a play on “atmosphere,” embodying an elevated brand that takes travelers to new heights through a visual identity reminiscent of an airplane window, inspiring flyers to dream. The soft gradients, smoothly transitioning in color and intensity, harmoniously weave together the blue of Alaska and the purple and pink of Hawaiian. The name also cues a promise of “most” – demonstrating the 11 years of Alaska’s Mileage Plan being named the number one airline loyalty program and cueing more rewards, more destinations and more choice.