What's the problem of just keeping the way to get new equipment like it always was?
Lunia has always had this system to open the box and win. Is there a problem with the players that have spare gold being able to buy the new gear? (considering that they might not have time to play all day)
If you wanted to use selenic as a requirement to have the Chaos items, you should have done it before!
If every new gear is untradable, as soon as people finish their sets they will stop playing because there is nothing to do after it. Just like it was with Selenic.
off topic: Why is it so difficult to not mess up the Guild Ranking Schedule?