People cant even seem to agree on what the ancient one meant. Marvel coulda been purposeful vague for all I know. I still assert that anything that gets changed causes a new timeline. Putting the stone back just stopped That time line from falling to complete darkness. It's the thorey that fits the best with what we see and the one the Directors seem to back. Only question is how Cap got back and where he got the Sheild. Did he make a new one or steal it from that timelines cap. If you try to fit it into one timeline nothing really works.