But there is a global timeline. The age of the universe itself. It happened when the universe was roughly 300M years younger. Somebody might say the universe was created a year ago if they traveled through it extremely close to the speed of light. But we know how fast we travel by measuring redshift/blueshift of the cosmic microwave background and it's definitely far from any relativistic speed. There must be some effect of gravity, but that is also within a rounding error. So, I'd say we are much closer to the "truth" than somebody who travels through the universe a few percent of the speed of light or "lives" right next to the supermassive black hole. Whether something we will never see exists or happens is a philosophical question akin to "if a tree falls in the forest..."