There are at least three aspects to language that we need to keep separate:
- Linguistic symbol (e.g. spoken or written form)
- Reference (things being talked or written about)
- Meaning (that which allows us to link symbols to reference)
When we ask whether a statement is "true" or "false", we are necessarily talking about a conventional expression--one that is contingent on the beliefs of the people engaged in dialog. For a dialog to carry off, the people engaged in it must share beliefs about the linguistic forms they are using. No linguistic expression can exist without that agreement or the context in which the expression gets produced. So it doesn't make sense to argue over whether linguistic expressions were true or false before humans existed. Linguistic expressions themselves can only exist in conversational contexts. They have no significance outside of that context.
Do things exist independently of human cognition? They do, but not in the way most people think they do. Reality is a bit like linguistic expressions in that the way we parse it is entirely conventional. Take, for example, the word "lap". Do laps exist? They represent a configuration of a human body. Laps appear when we sit down and disappear when we stand up. There was a time when no laps existed, and none would exist today if all humans were to stop sitting. What would a "lap" mean to an ant or a snake? Neither creature has a body that can sit.
So, are "laps" absolutes in any sense? They exist in the outside world. They are part of reality. But they only exist as constructs in the minds of beings with human-like experiences.