Fatal for the completeness of chronicled words and meanings. In time fatal for languages that will die out as well.
Strong is fine. We will always gain more, but that's nothing we can influence to begin with. Languages will always grow with use, even when people try to stop it, so it becomes even more pertinent for academics to properly chronicle everything. Human history is still young; I don't want to see us unaware of the very first occurances in any example at all. I know it will keep happening, but whether a principle will be honored or not is up to you, and you alone. It's not impossible to minimize the loss, so there's no reason not to. This doesn't cut short on understanding in any way as far as I can see, since public use and academic use are separate. As I said, I don't mind anglicizing.
I'm not looking to change any course. The point still remains that we don't know of its the first occurance of the word. We can't change that now, but we can, however, make sure future linguists can be sure where, exactly, we got it from.