This is how I think it went down
Gorosei knew that there was a fruit that once belonged or resembled Nika's
Since it's never been awoken for over 800 years, they thought it was a myth
They also knew the fruit was renamed to something else at one point (obviously don't know what)
Shanks come to them at the Reverie and warn them about Luffy's awakening
Gorosei are aware of that but they just bundle Luffy with Kaido and BM and don't single him out
Zunisha also arrives to Wano
Gorosei know she was Joy Boy's nakama and start panicking
"What if Shanks was right and Straw Hat is about to awaken"
Gorosei send orders to kill Luffy immediately
Gorosei knew that there was a fruit that once belonged or resembled Nika's
Since it's never been awoken for over 800 years, they thought it was a myth
They also knew the fruit was renamed to something else at one point (obviously don't know what)
Shanks come to them at the Reverie and warn them about Luffy's awakening
Gorosei are aware of that but they just bundle Luffy with Kaido and BM and don't single him out
Zunisha also arrives to Wano
Gorosei know she was Joy Boy's nakama and start panicking
"What if Shanks was right and Straw Hat is about to awaken"
Gorosei send orders to kill Luffy immediately