I do agree with some of the things Syntax said. Most of the members join this forum because of neopets. Even if neocodex continues to run after neopets is closed down, there will be a lot less active members.
However after joining, many also get to knbow some new friends, it become a community here. It will be sad to see either neopets or neocodex goes down, personally I do not mind to pay a few dollars each month to keep both sites running (for Advance here and Premium in neopets). I lost many good friends when 3vo closed down and when I quit playing neopets some years back. I would hate to see that happen again.