REG
A player’s hand is where a player holds all the cards that are not in their deck, Reserve, discard pile or banish pile but have not been played. Players put cards from their hand on the table to play them. By the end of each of their Discard Phases, a player must reduce their hand size to a maximum of 8 cards, unless modified by a Change Hand size effect.
So, the syntax of this explanation is all players have to put their hands to 8 during all Discard Phases, correct?