Suggestion from a CERN user:

I am suggesting adding the item 'Reset approval/rejection' inside the menu "Moderation" which is used when we want to approve or reject a participant

It is true that this is not something we often do, but it is a lot more intuitive to go into this menu for "Moderation" and select from there the action "Reset approval". It was not intuitive for me to find this action by looking at the person. In addition, if you provide this action inside the menu, we can do it in "bulk".

My use case was:
I accepted too quickly some people and I wanted to reject them because, with the company name, we suspected they wanted to come for commercial purpose. These people replied that it was not the case.
Can you make this modification in Indico? I think it can be useful for other people who may have the same problem than I had in order to find how to cancel my rejection.

I think it's a pretty rare case, but considering that we have bulk approve/reject (and neither of those actions will overwrite the status of a registration that's already been moderated), it kind of makes sense to have bulk reset as well...