Like Friiday has mentioned it is a very low priority. The server is as you can tell, manly PvP based and though many people liked Creative it was not the largest source of player income. Also with the newly added UHC game mode, and the server/forums update the Developers need to fix bugs and add more to the servers. I am sure it will come back eventually due to the many requests to do so. Meanwhile, I recommend playing UHC and SG both very fun game modes on the MCG Network.
As stated above, creative is going to be coming back. As of now, there are no for-sure plans for creative; however, there are a few things to know. For one, creative is going to be rebuild from the bottom up. In addition, it is important to know that the devs have higher priorities such as bugs and new features. After those are done, creative will be worked on and hopefully be up. Expect it to be up later this year, but not any time soon.
If you have any further questions or concerns, feel free to contact a staff member.