Cut out all the fat in this post. This is the only important part of it.
Yup, you've got it right here, thank you for this answer.
His title's just that- A rumor.
It's not official in any way. So putting Kaido above Xebec, Imu, Whitebeard etc. based off it makes no sense just like it makes no sense to put him above Mihawk because of it (as you yourself admitted in this very post).
I'm glad you finally stopped ducking me and just told me outright that it's not an official title like WSM or WSS are. Thank you for being humble here.