A changed arrangement deserves words before it becomes someone’s surprise.

Plans that change quietly put the cost onto whoever finds out last. Arriving to a locked door, or hearing from a third person, does more damage than the change itself ever would, because it tells someone they were not worth a message. Most of the time the silence is not unkindness but avoidance: telling people feels like admitting a small failure. The delay makes the eventual news heavier, not lighter.

When something you agreed to shifts, send the short awkward message early. Two sentences, no defence, and an alternative if you have one. People forgive changed plans far more readily than they forgive being left to discover them.