The word "more" signifies an increase, addition, or higher quantity. Therefore, its antonyms pertain to lessening, diminishing, reducing, decreasing, or minimizing. Henceforth means from this point on, therefore the antonyms of "more henceforth" can be seen as "less from now on", "lower in quantity", "minimal in amount", "reduced from this point on", or "decreasing henceforth". These antonyms can be used to describe situations where the presence of something is no longer as required or it is decided to decrease it. "More henceforth" is a phrase that is often used in academic or business writing when outlining plans or strategies for the future.