I do feel WG came to know about Teach's bloodline but after he became a yonkou.
We have elder talking about it.
Perhaps Teach laying low and then allying with WG until he got his hands on Gura really outplayed WG
We have elder talking about it.
Perhaps Teach laying low and then allying with WG until he got his hands on Gura really outplayed WG
Still though I know it most like just plot restrictions but they should've know Teach had some ties to Rocks given how much of an oddity he is

- Doesn't sleep
- Weird body constitution
- Able to use more than one DF
etc.
Except of course Teach doesn't share any of those traits with Rocks.