Yup. Many cars without heater cores come with plugs on those attachments.
If there's nothing wrong with the hose, though... just keep it as is... changing it for plugs won't give you any extra security... in fact, pressure building up behind the plug might make it worm its way loose over time... happened to us in a Civic a few years back... we replaced the plug with a rubber cap meant for the leg of a footstool and fastened it with an O-ring (this happened on a Sunday... no auto-shops). Far as I know... now that the car is with the next owner... that cap is still there...
Keep the hose... or just replace it with another one.