Replacement WD Red Drive has Warranty 2 years shorter than RMA'd drive

I am in the middle of an RMA at the moment.  Today I received a replacement drive and the warranty checker says the warranty expires in less than 4 months.  The drive that I will be mailing back has OVER TWO YEARS of warranty remaining. What gives?  I’m not really going to lose 2 years of warranty coverage am I?  

Hi once they receive your old drive the warranty will change to the 2 years again.

OK, thank you very much!