The Captain Phasma comic does as advertised since they don’t tell you just how long after The Force Awakens that it will go.
Lucasfilm works hard to make sure that the Star Wars franchise stays consistent and relevant across many mediums and the new Captain Phasma comic should fill in the gaps between The Force Awakens and The Last Jedi for the character.
The Captain Phasma number one comic will focus on her escape and the events leading up to The Last Jedi.
As previously mentioned, the new Star Wars comic, Captain Phasma number 1 packs a lot of information into its pages.