There were things that Oriole did not know about, and Arthur realized that when he asked him about what happened in the Trial of Holy Crown. Ori mentioned that there were things that he could not ask about, lest the previous Arthur mistrusted him.
Arthur could not agree more. If Oriole had arrived with knowledge of the future and tried to convince him that he needed to follow a specific timeline, it would have been the same issue as his father's.
Even though it gave Arthur complicated emotions, he still believed that he did the right thing by overwriting this timeline. However, sometimes when he closes his eyes, he can feel the other Arthur staring from behind a glass.
However, that previous Arthur refused to give up the memories he created and his choices. This left the current Arthur helpless when faced with Miko, who seemed to hate him now.