Let me explain why, to me, this place isn't in past.
In the very beggining of the game, you just walk through to the shrine and you have no other choice than teleport to lothric. You can't walk anywhere from cemetery of ash and firelink shrine. Thats because it is actually another dimension.
Once you teleport to the Lothric, even without touching any bonfires, you can walk to the untended graves, which means all the game map that we have been playing mosty has dark firelink shrine and untended graves as default. The place where we start to the game is totally diffrent dimension. Thats actually why its not past, because when you use bonfire of main firelink shrine and teleport to the world we have been struggling, some npcs we meet immediately gets into our *hope* dimension and we meet them in shrine. The place we teleport at first of the game, starting with lothric, is actual dark age, which means those eyes of firekeeper we found makes our firekeeper to fell into depressive mood. Eyes just shows her the place where we teleport at first, the dark age. Also if you read dialogues of Twin Princes, they want you to let the world fall into darkness, so they already know we came from the dimension of hope to link the fire, and the reason we are struggling on this dark age is actually that its the dimension of "TRUTH".
Champion Gundyr is actual form of Gundyr , who was late to get his quest done. Iudex was having diffrent role with sheathing for coiled sword in our "hope" dimension.
well thats my idea and since untended graves share same earth with all other areas except first area ( cemetery of ash and first firelink shrine ), its not past. Another dimension, actually all dimensions bind into betrayal scenario, but even if you do something cool and save the world somehow, something from other dimensions can pull your's into darkness too. Because even after killing evil bosses from your own truth, you can go to other player's worlds and still kill those again, vice versa, your truth can be runined in anyway. Dark souls has a stupid anime-like tryhard lore, i can almost hear game itself screaming, i am god damn japanese game! Nice hopeless and desperate universe design though. I would like to world to be destoryed so there will be no more problems in my opinion... Poor souls, struggle all the time, and efforts are nonsense. Im glad there wont be another dark souls game.