Teach will kill him after killing Akainu, Imu and Mihawk.
See, i question that. Not only because its such an overplayed "theory" this fanbase has come to accept for some reason, but because you have the WSC explicitly stating that Haki trumps over all.
If we compare essentially anyone on this list, Shanks clearly has the most broken haki in this franchise and no one currently seems to come close onscreen.
So the concept becomes this, is power a reliance on your devil fruit or haki or both? And IMO, Blackbeard, Shanks and Akainu represent this respectively.
If Blackbeard has 3 fruits and the 3rd is a zoan, he is essentially representing the Devil Fruit argument (he has shown minimal haki, but yes Im sure he is up there too). We know Akainu has both top haki and an extremely powerful DF. Then you have Shanks, no fruit, but basically just Roger in portrayal.
This is why imo all 3 are going to be involved in whatever major conflict comes after Elbaf. Because they all seem to represent each. Luffy technically is the same argument as Akainu but with a Mythical. Then you have Buggy who is a Paramecia lol, but he has no Haki.
And who knows what Imu actually is (we just assume Zoan but can never be sure)
Tldr: The 4 Yonko and Akainu are basically a pentagram of comparisons between Devil Fruit Classes and Haki. Can we truly argue that Shanks, being the only DF-less Yonko with the most broken Haki, will lose first?