If the old servers were locked from starting new accounts, and each player had 1 invite so a friend come join late, and invites then would only be given to new accounts after they reach level 70, this could possibly prevent the downside of alts in the trading idea.

i have so much stuff i could trade off to guild members, small chips, old plan, hero cards ive already sainted to the max, all this would help a lower level player progress, and as people see progression they tend to spend money to continue that path at a steady rate, so tynon it would be a win win, happy customers and money lined pockets.

We dont need no more accounts on s1 so im guessing that the other original servers are similar.