Or knew “the one” had to be someone who ate the Nika fruit.
I don’t think Shanks had Luffy picked out as “the one”, but Luffy eating the fruit forced him to try and salvage his plans by betting on Luffy able to become “the one”.
indeed,,it couldn´t be other than a Nika User of course--and now that he awaken G5 More than ever... i wonder,, if from the moment he took the Fruit from the CP9 Ship, at some point he could have believed He was the one,,, since he could have eaten it at any moment, but Fate (when Luffy stolen it at the bar ) Proof it otherwise,,
Lot of questions here on why he doesnt eat it Asap ,,¿ what he was planning to do with it ? ¿ was he taking it somewhere?,,(not with a lot of rush considering he stopped on a Bar to drink) , ¿Maybe he was waiting someone eat it ? in sense to "Leaving it all to "D."estiny"
Nika fruit is not a Normal Fruit, got a will of his own,, the fact W.G couldnt get it and lock it in a basement in Mariejois in 900 years, proof it,, i think Shanks Knews this, and knew, whoever took it in that Bar,,it was really the ONE perfect User for it..