Photo Credit: Lucasfilm
3. Could this character show up in Han Solo’s upcoming movie?
Though this theory isn’t directly linked to the show itself, it does suggest what may happen to Kanan’s character after the show ends.
"“Solo: A Star Wars Story is set in the gap between Revenge of the Sith and the first episode of Rebels, which happens to be a period in Kanan’s life that is mostly unaccounted for in canon. The new movie could take place at the perfect time for an appearance from young adult Kanan” – Cinemablend"
Put it this way. If the writers can do crazy things like having Anakin repair C-3P0 as a child, then they can stick Kanan and Han Solo in the same room together.
Star Wars Rebels fans will know that Kanan used to be a padawan by the name of Caleb Dume. But he ran off when Order 66 killed almost all of the Jedi. He then became Kanan Jarrus. The only novel that talks about young Kanan in this part of his life is A New Dawn.
It mentions him being an alcoholic, in simple terms. Solo: A Star Wars Sory is set between similar time-frames as Kanan’s youth-hood, both of them ending at the start of Star Wars Rebels. The most we could get is a long shot of Kanan in some space-bar, as the A New Dawn novel describes it as.
Cinemablend found a screencap from the trailer and explained that this setting is a place young Kanan could likely be found in. It looks like some sort of intergalactic space bar.