No! xd No more! As someone that is almost halfway to Emperor (117m away from getting it) I can say that there most definitely does not need to be more. Emperors will still have plenty to do, especially building, and working on getting collections and things.
The entire point of getting to emperor is to "beat" the server. To get the highest of the high, top of the top, and then retire to (generally) non-competitive things such as working on your town. That is the 2nd level. Just being able to relax, and fly above everyone that is toiling to reach your level.
In addition to what Collector said, it could also include trying to be at the top of McMMO total, specific McMMO stats, Number One on /baltop, and more! There is so much more to the server than just "get to emperor." You want to become the best in the stats!