I believe a significant factor in the TRU situation was that they had already filed bankruptcy. Mattel has not done this yet, but there is a real possibility they could be there within the next year.
For the people who were recently laid off, I expect their severance should be safe.
For current employees, you’re going to have to wait and watch the market, and try to make an informed decision as far as how long it’s worth it for you personally to stick around. You do have a choice, and I’d encourage you to consider what else you might do if Mattel is not the best choice for your career. Don’t be passive in this; you’ve got to look out for yourself and your family.