Eh. This is pure headcanon unless we some how get a flashback and see if Shanks saw something.
For now it just seems that he wanted to drive Aramaki off because he thought the alliance was wounded.
Call it however you like at the end of the day everyone has his agenda.
But tell me without any bias.
It does look cool and factual.
Shanks and Kidd situation:
Shanks is slowly approaching shores, uses FS and sees a tragedy, he is mad u can see it on his face and goes to prevent that tragedy.
Ryo situation:
Shanks sends Conqueror's Haki wave to send a message and when we see a close up on his face he is mad as fuck ( even more mad than at Kidd ) and threatens Ryokugyu.
Shanks wasn't close so it is not far fetched to claim he used FS and saw what Ryokugyu was about to do.