1) You don't have to sterilize your containers or equipment - you Sanitize them and you need to look into the difference.
2) What you are suggesting might not cause any problems.....but why do you want to risk your time and money on possibly infecting that new wine batch with a bacteria or mold that may have crept into that old wine? If you are talking about homegrown grapes or fruit still there is the time and effort wasted should something cause that new wine to go off the rails.
Edited for one additional thought - Do you wash pots and pans after using them to cook? Why, wouldn't the heat sterilze the pan or pot? Same principal, unless you don't wash your pots and pans.