The following contains a spoiler for Solo: A Star Wars Story.
Solo: A Star Wars Story gave us a lot of brand new information about some our favorite characters in the franchise, but one of the most intriguing new details was about our favorite spacecraft. The new movie reveals that Lando's co-pilot, L3-37, actually has her databanks dumped into the Millennium Falcon, making her part of the ship forever. It may seem like an odd way to go, considering this is never referenced anywhere else in the Star Wars franchise, except, it turns out maybe it is, as a line from Star Wars: The Empire Strikes Back now has a very different meaning based on this knowledge.
The Millennium Falcon is suffering from all sorts of technical problems all throughout The Empire Strikes Back. Han Solo has C-3PO interface with the ship in an attempt to discover what is wrong with the hyperdrive so that they can use it to escape their Imperial pursuers. This interfacing leads to the line above, as the droid tells Han that the Falcon's dialect is a little strange. As the Star Wars Twitter account points out, that peculiar dialect is apparently due to the remnants of L3-37 inside the ship.
Certainly, no other droid that we have met in a Star Wars movies is quite like L3-37. She's more self-aware than any other droid we know and is vocal about the rights of all droids. While C-3PO is a protocol droid and therefore is fairly proper, L3-37 doesn't mind getting a little rowdy or dirty. It's not shocking that 3PO would find her "peculiar." If only we could actually hear what she said.
The issue with making prequels that were not part of a larger plan at the beginning is that it becomes difficult to create anything new that feels important because it never gets referenced later in the chronology of the story. Here, it appears that writers Lawrence and Jonathan Kasdan found a way to work backwards, by taking a line from the original trilogy, one that didn't really require an explanation, and using it to connect to the story they were creating. It works well as far as it goes. The moment in Empire now becomes an easter egg of sorts, the kind that will be completely overlooked by any that aren't aware of the connection, but that can be fun for the fans that know what it means.
Solo: A Star Wars Story is guilty of giving us a lot of answers to questions that most people never asked, but with the possible exception of feeling a need to explain the title character's name, most of the answers were handled well enough. Fans of L3-37 will now think of her whenever they watch the original trilogy, as they wonder just what she's telling C-3PO, probably that he doesn't need to serve these people.