Speculations Act 3 is the last act of Wano.

[KAIDO D. STRONGER]

When the hybrid kaido appears, it will really be to close the curtains of this third act, to notice that no subordinate of KAIDO is fighting in its strongest form, nor have we reached the peak of the fights yet the hybrid will turn the tables and the war the hybrid + awakening.
Be prepared, to see the WSC, WSM, WSP, king of 1x1, fight.

 

[Drachenblut]

I believe at the end of the wano arc, the red hair pirates, the bb pirates, at least 2 admirals and the revolutionaries will come to wano.
So wano will be a gathering of the worlds strongest forces. They won't figth though.

So I believe 5 acts to be accurate, since there is much more to happen (imo)

 

[Don DaSlayer]

Bro you guys been saying since the chapter 975 that the act was going to end in the next chapter We are on chapter 1005 now.
The Raid 100% not failing. Morj started this creditless thing. Breh If the raid fails then the Strawhats die.

 

[Warchief Sanji D Goat]

He literally never said this about wano that's Artur piece. He was talking about the final war

Do you have the actual source on this?

 

[ArturCantSpeakJapanese]

Do you have the actual source on this?

from jump festa 2018:
"Hello. It’s Oda. Are you enjoying Jump Festa? I am also watching the One Piece Super Stage Event. It’s fun. Each year I visit Jump Festa and eat with the voice actors. One Piece will finally go to Wano next year! Some of you may remember I said this last year. I did think that Wano would start in 2017. I have some new information, I will introduce a legend lying dormant in the One Piece world. The strongest enemy the Straw Hats have encountered. It may be related to Whitebeard. The Marineford Arc will seem cute compared to what is coming."

What will make marineford look cute is the lurking legend and "strongest enemy" that may be related to whitebeard. (Blackbeards 10th captain? Shiki? Shanks? Who knows) This character may be introduced in wano but it does not seem to be Kaido or the wano arc itself because Kaido was already introduced and discussed at this point.