We have a case where we use an automation button to move a card across lists, mark a due date as complete and remove all people but the person whom presses the button.
People who have contributed to the card sometimes seem to maintain their watch status, but for reasons unknown to us, sometimes they don't. We've tested many variables about how people come to watch a card (added as a member, added comment, added a comment with a tagging of someone), but it's still inconsistent.
