So have you been furloughed? If not, what's the big deal?
In my prior life, I was a computer programmer, and my last programming job I landed through an agency. The agency charged the employer a fee, but I had to sign a contract with the agency that if I was placed and then left the job within six months I would be responsible for paying the agency fee back to the agency. The reason for that is because the agency offers the employer a money-back guarantee on the agency fee, so if I cause them to have to refund the fee, they still make their money. I worked for that company for well over the six months, by the way. (I was there for a little over six years before leaving to pursue a career in aviation.)
My point is, if the company invests money in you and offers you continuous employment and you choose to leave during that first year, you SHOULD pay them back. If they furlough you, I don't think they have the moral high ground (but you still shouldn't sign an agreement you don't intend to honor).