Invites are now open for all classes, again. You will have one month (four weeks) to send the invites, to whoever you feel like. After the month, the rules voted by you regarding invites will be enforced. Which also includes the invites being removed from the market, but you will still be able to send out invites by sending a staff message.
The accounts who haven't been used more than two months, will be disabled by a script which will run once at 6 months.