Kyoshiro = Denjiro. It's as clear as day.
-Their names are almost identical, especially in the original japanese text when both names are written the same
-Denjiro was introduced as great with money and Kyoshiro is the money exchanger of the Capital
-He was the first Scabbard to heed caution over Orochi
-As time went on, he started resembling Kyoshiro more and more
-He left Hiyori alive, saving her
Zoro, who's unarguably received the most focus outside Luffy this arc, is not about to have his big fight and moment against a clear ally to the cause. There's nothing being accomplished that way. Oda keeping Kyoshiro ambiguous this far into it is proof he is not a villain, because it's either he's an ally or usurps Kaido and Orochi as the villains, latter being unfeasible at this point.
It's like concluding Sanji's big fight this arc will be against Drake.