I hope the spoiler are true...
G4 Luffy,Jack,Kaido and the others, we literally have anything.
And if these spoiler are true, you can expect that Luffy now can use G4 as he can use G2, because he spamming it now without worrying much about it. I think he didn´t have a timeproblem anymore because of controlling his haki very good.
I expect another G4 or even G5 form against Kaido.