Unless something has changed very recently, it has always been 20 years. He might be talking about the Navy Reserves HYT which is 22 Years for E5 and 24 for E6. Ask your Sailor where he got his info from. It might just be messdeck rumors.
If there is any changes to HYTs then there will be a NAVADMIN released on it. You can find all NAVADMINs posted on www.npc.navy.mil