The antonym for "more excitedly" would be "less excitedly." This indicates a decrease in the level of excitement or enthusiasm. Other antonyms for "more excitedly" could be "calmly," "nonchalantly," or "dispassionately."
In situations where someone is trying to control their emotions, they may choose to be less excitedly. For example, when receiving good news at work, someone may choose to remain calm and composed, rather than reacting more excitedly. In other instances, a person may simply not be interested in a particular subject, and therefore would react less excitedly.
Regardless of the situation, the antonym for "more excitedly" helps to establish a clear contrast in emotions and behavior.