Yes, but it means nothing.
The first adjuster an unrepresented auto injury claimant deals with is usually a lower level adjuster with limited experience. These adjusters are often given some "tools" in an effort to minimize the settlement payments to the injured motorist. One of them is a veiled threat to close the file should the injured motorist fails to respond to an offer to settle the injury claim.
An insurance company adjuster can do this, but it really doesn't mean much. Under state law, you have a certain amount of time to have your claim resolved by settlement, or filed in the appropriate court. This is referred to as the "statute of limitations."
In Oregon, you generally have two years from the date of the collision to have the case resolved by settlement, or filed in the appropriate court. Please be aware that this time limit applies only generally, and there may be other deadlines critical to your case. For example, you may have to file tort claim notice against a government agency. For more information on tort claim notices, check out this article.
If you suffered a minor injury, and wish to resolve the case on your own, don't rush. Take a few months to make sure that you are able to do all the things you were doing before the injury before signing a settlement agreement that forever releases the insurance company from any responsibility for your injuries.
If your collision occurred in Washington State, then you have three years from the date of your injury to resolve the case by settlement, or file it in the appropriate court. Remember, other time limits may apply. Remember too that your best bet is to wait until you have completed treatment, and nowhere you stem medically before approaching the insurance company about settlement.