Yes, but was it implied? Strictly spoken I can't find anything stating clearly that you can achieve creating an MMOG using only 3dgs functions. You'd definately need a database at first, so you will need to make use of plugins already. The fact that you cán use plugins for enhancing your development makes it possible to create a MMOG. The engine just helps you rendering everything, and it's being a big help there.

I too would have loved it when 3dgs supported database connections and more than only directplay, but marketing or advertising-wise, they did nothing wrong. It's what every company does to sell it's product.