You know, the consortium also approved the slightly smiling face,[1] which should show content without being so exaggerated. Also I would never thing that your example in 2 would be expressing exhaustion, the mouth closes in the middle like the face is crying, not like it is out of breath. To me the weary face on iOS 11.2 looks like "poor you, i'm so sorry"

[1] https://emojipedia.org/slightly-smiling-face/