You must not have read this part
So, given the opportunity to speak with father-and-son “Solo” co-writers Lawrence and Jonathan Kasdan, I asked them about Lando’s possible sexual fluidity. Is he pansexual?
“I would say yes,” Jonathan Kasdan emphatically said.
That's what the writer of this particular film believes and wants. Until you see Disney cosign it and reference it in a movie, it isn't official.