Here are some info that make me believe that Zoro is the one who inherited Oden’s will and it make me believe Zoro will finish what Oden couldn’t.
And let’s not forget that Oda already made a lot of intentional parallels between Zoro and Oden.
First, they both have no navigational skills.
Oden met a 26 years old Toki.
Zoro met a 26 years old Hiyori.
Oden saved Toki and fainted.
Zoro saved Hiyori and fainted.