So this is something that just came to me. Let's say that by the time of A New Hope Yoda isn't alive anymore (maybe he didn't survive his duel with Palpatine). Obi-Wan Kenobi is now the last of the Jedi. Flash to the moment when the Millennium Falcon is captured by the Death Star. Obi-Wan senses that Darth Vader is on the space station. Luke hasn't had any real training and if Obi-Wan dies there's no one left to finish his training. What do you think Obi-Wan's next steps are? Especially if he meets Vader (like he did in the film) and they duel. Do you think he still sacrifices himself to allow Luke, Han, and Leia to escape?