So long, Extended Universe... many Star Wars fans will miss you (I will most definitely miss you)!
When Disney purchased the rights to Lucasfilm, they officially declared the Extended Universe (EU), that has been built by hundreds of writers and artists since the end of Return of the Jedi, dead. Really, everything (including one of the most deadly Force users in the universe and no, I'm not talking about Luke) was considered not canon, leaving room for Disney to write an extended Star Wars universe of their own.
However, Solo: A Star Wars Story writers Lawrence Kasdan as well as his son, Jon Kasdan, were influenced greatly by the Extended Universe, so much so the film pays many homages to the former stories.
"I’m lucky because I know nothing about the Expanded Universe," Lawrence admitted when he spoke about writing Solo. "I had never read one of those novels, so for me, it was always starting from scratch. And Jon, who’s much more converse in that stuff, would sometimes say to me, ‘But here’s what happened.’ But we never felt limited by it."
Thank the Force for Jon Kasdan, seeing as he grew up with Star Wars and benefitted by his father's involvement with the original Lucasfilm productions, seemingly continuing to read the stories that were published afterwards.
Serving as the encyclopedic foundation for all the ties to the Extended Universe, it seems younger Kasdan integrated aspects from the old stories into this new one.
For instance, hasn't anyone really wondered about "Solo Luck"? It really does play a part in the Extended Universe, and one of his children actually brings up an interesting theory which she believes true because of her understanding of the Force as a Jedi Master. (Yes, in the EU, Han has a daughter... but notice I said children. He does have a son that goes dark side... so, there's that).
Anyway, there's only a few days left until Solo hits theaters and goes about reintroducing a beloved scoundrel and some old friends (and maybe some old made the new canon?)!