He might know a lot more about it than they do as he is well researched on DFs, having that book on DFs and such? Unless this is gonna be another stupid gag moment by Oda? Blackbeard just wanting it for typical lecherous pirate reasons?
I'm hoping there's some secret to her DF that would justify him wanting it so much, I mean this is the thing we've been waiting maybe 2 years to find out what he was after? At least 2 years anyway? I think his panel about going after it was after Act 1 or 2 in those intermediate chapters outside Wano?
I mean its weird a love based fruit turns people into stone...why not just make it a Medusa mythical Zoan?