I think Oda is hinting that Imu will eventually witness Chopper’s Devil Fruit and realize it can counter his powers.
From that, Imu could recognize that Chopper’s fruit isn’t normal, but something far more significant like possibly even a “god” Devil Fruit. That might also explain why Blackbeard was in Drum Island in the past Looking for chopper DF
If that happens, Zoro would likely step in to protect Chopper from Imu. After seeing the threat Chopper poses, Imu could then order the World Government to prioritize capturing him because of how dangerous his Devil Fruit is.
could see 2-3 Billion for chopper ngl