Time is not linear. You cannot erase the past without also erasing the future.

There are already multiple timelines, and so, the information of them, does not limit the future tied to them. All meaningful information is stored as long as it is needed.

The entire idea of black holes was laughed at until a lot of rock-e-person money was thrown at it.
Yes, scientists are trying to find evidence of a black hole, so they look and they see something, and then incorrectly attribute it to a black hole. There are many other models, which match the data far better, far more simply and far more elegantly.

When we start looking at the universe with huge long distance dual-optical scopes, we will start seeing the actual structures of our galaxy and how they all tie together.