Solo: A Star Wars Story is set to tell us about the life of our favorite outer space smuggler before we met him in Star Wars: A New Hope. However, the new film would be quite different if the prequels had gone the way George Lucas originally intended. The original plan for Star Wars: Revenge of the Sith included a brief appearance by a child Han Solo, which, if it hadn't been cut, would have completely changed the direction that any future Solo movie would have gone.
The Star Wars prequels get a lot of grief, justifiably for the most part, for taking a crowbar to the story in many places in order to force references to the original trilogy that don't need to be there. R2-D2 is there from the beginning, C-3PO gets built by Anakin Skywalker, it gets awkward. However, there was almost an additional character from the main trilogy who appeared in the final Star Wars prequel. Originally, George Lucas had a ten-year-old Han Solo on the Wookiee planet Kashyyyk, being raised by Chewbacca. Child Han was going to even play an important role in the plot, by finding a piece of a droid that was still transmitting, allowing the Wookiee forces to track it back to its source.
Eventually, the scene was dropped, and with it, the inclusion of Han Solo in the prequel trilogy. However, had it been included, we certainly wouldn't be getting the version of Solo: A Star Wars Story that we're getting next weekend.
While there's a lot we don't know about how Han Solo's early life will be depicted since the movie isn't out yet, we have seen enough to know that Han and Chewbacca will meet for the first time in the movie, when the title character is much older than a 10-year-old child. The original trilogy never presented Chewbacca as a surrogate father, but if the prequels had done that, any Solo film set between the two trilogies would have had to deal with the concept. We don't know who raised the Alden Ehrenreich version of Han Solo, but it probably wasn't Wookiees. Clearly, if it had been, he'd have a much different origin than the one we're going to get when Solo: A Star Wars Story opens next weekend. Somehow the new movie would have to account for what we saw in Revenge of the Sith.
However, since the idea to include child Han was cut, the writers had a free hand in creating the backstory and figuring out how the relationship between Han and Chewbacca would begin. We'll get to see what the "officially" looks like when Solo: A Star Wars Story opens May 25.