What model is Boeing's newest aircraft, introduced in 2019?

Boeing's newest aircraft introduced in 2019 is the Boeing 777X. This aircraft represents the latest generation of the 777 family and features several advancements, including the world's largest commercially available twin-engine jet, innovations in aerodynamics, and new engines that improve fuel efficiency. The 777X also includes a larger cabin with more space and modern technology for a more comfortable passenger experience.

Though the other models mentioned have their own significant features and were designed for different purposes and markets, they do not represent the newest entry introduced specifically in 2019. The 787 has been in service since 2011, the 737 MAX was introduced earlier and faced issues before its return, and the 747-8 is an iteration of an older design and was first delivered in 2012. The 777X, therefore, stands out as the most recent aircraft model brought into Boeing's lineup, marking a significant development in long-haul travel capabilities.