Bug 12630 would remove the ability to insert a new hold into the middle of the holds list based on the future hold date. This is good, as the current behavior allows for "cheating" the holds system to get his or her hold pushed higher up the list of holds. A better solution would be for the holds system to skip over any holds where the hold date is in the future. With this behavior, bug 12630 could be pushed, but not allow one future hold in priority 1 to keep any holds after it from being filled.
This does actually seem to be the case, bug 9761 even allowed for lookahead to capture some of these. Tests added on bug 12630