Since this game is meant to help bridge the time period between the original and prequel trilogies, it would make sense to include at least one character from the prequels in it.
Bail Organa, the adopted father of Princess Leia, was instrumental in the formation of the rebellion, and was also a known friend and admirer of Jedi, helping both Yoda and Obi-Wan Kenobi go into hiding after Order 66.
Since this story is canon, Bail seems like a logical choice to include in it, as when Cal resurfaces as one of the few remaining Jedi, he could be one of the first to offer him help to escape the empire, and possibly be the one to recruit him to join the rebellion.
From what we have seen in the trailers, Cal will start out the game’s story in hiding, working as a scrapper before his cover is blown and he goes on the run, but in the game-play released at E3, he is on a mission with rebels to free a group of Wookiees imprisoned by the Empire.
This implies that he will need to be recruited to join the rebellion to help fight the Empire at some point, and Bail could be the one to do it, as he goes on to instruct his daughter to do with Obi-Wan to help deliver the stolen Death Star plans in A New Hope
Actor Jimmy Smits recently reprises this role from the prequels in Rogue One: A Star Wars Story, and it was a very nice cameo to see in the movie, as it helped to bridge the two different eras of Star Wars films, so if they were to get him back to help bridge the movies with the video games, that would be all the better.