The first question savvy fans might have after watching The Last Jedi is, why the heck wasn't Captain Phasma killed (or at least heavily punished) after basically letting the Resistance waltz onto Starkiller Base and lower the defensive shields in The Force Awakens?
Well, first off, Phasma went into the computer system and framed a lowly lieutenant for that little security breach. Easy peasy.
Secondly, Phasma actually holds a lot more sway in the First Order than the films let on. Aside from Supreme Leader-slash-hobgoblin Snoke, the First Order is controlled by what StarWars.com calls a "triumvirate" of commanders–Kylo Ren, General Hux, and Captain Phasma. Phasma's specific job is to be, mostly, a chrome-plated badass, but also to oversee all the other stormtroopers in the First Order.
She also occasionally steps in and personally trains some of the troopers, notably the FN Corps–which you might recognize as Finn's unit. So to say that Phasma, who personally trained the turncoat who helps destroy almost everything the First Order throws at the Resistance, plays a crucial role in the story is putting it mildly.
Will we ever know for sure? Let's be honest: falling into a fireball has historically killed, maybe, three percent of movie villains who didn't show up again in the sequel. So call us crazy, but our guess is that Phasma will be back for Episode IX.