I change my opinion when I get new information. Growing up, I thought Goldeneye was the best first-person shooter in the video game world. And then Perfect Dark came out, and it was literally just a better version of Goldeneye. My opinion changed: Perfect Dark took the top spot in my rankings. (Don't even try to argue with me about this.)
The same logic applies to fantasy football rookie rankings. Those rankings will change with new information. With the NFL Draft still to come, there's a huge piece of information missing in rookie evaluation.