There has to be some empirical data that could answer this: Changing your oracle picks: hurts more than helps or the other way around?

This would very likely be totally neutral.

There's a slim chance it would be very slightly positive on average, as people might be taking into account new information (pictures etc.).

There no way in hell, absolutely guaranteed, that on average it would be negative.

People's biased memories are completely psychological - but of course that goes without saying :)
---
www.gamefaqscontests.com
www.gamefaqscontests.com/gallery