The phrase "shutting the door on" typically implies a sense of finality, conclusiveness or rejection. Some possible antonyms or contrasting expressions could include departing from but leaving the door open for a potential return, keeping the door ajar for further communication or negotiation, giving a second chance or reconsidering a previous decision, accepting an invitation or opportunity, ongoing collaboration or dialogue, opening up to new possibilities or perspectives, embracing diversity or multiplicity, showing empathy or respect. In other words, avoiding the binary, one-dimensional mindset of shutting down options or people and opening up to the richness and complexity of life.