The Family and Medical Leave Act gives you up to 12 weeks leave and prevents you from being fired/terminated for using that leave; however, it does not prevent termination for unrelated reasons, whether provable "for cause" grounds related to you personaly or for broader organizational changes/restructuring. If this is a legitimate restructuring, they can terminate you; if you believe it is a pretext or excuse to fire you due to your leave (e.g. only *you* are being restructured) contact the state department of leave to file a complaint.