Some people cannot handle the truth. This information is too scary to process for many. Most prefer to stick their head in the sand and hope that this problem will go away. The paycheck is still coming in on time. Everything will work out. Everything will be fine. Unfortunately NOT.
You have done your best to warn others about the upcoming layoffs. Now do what you can to help yourself weather the storm and stand ready to assist others as some "may see the light" before the layoff sees them.