If a gift that was matched is refunded, will the matched money return to the match pool?

It depends on on whether the match was still active and had available capacity when the refund is processed.

If the match had remaining capacity and the end date had not passed: GiveCampus automatically restores the refunded gift’s contribution to the match pool. The match will reflect the increased capacity for future gifts.

If the match was fully exhausted or the end date had passed: The system does not automatically restore the match funds. In that case, you must adjust the match total manually to reflect the change.