Looks like The DCL Wonder will call at Key West and Galveston as alternative US ports in addition to Costa Maya and Cozumel. There is a lot of cool things in Galveston to do as a port of call and they would be unique to do it. European cruise ships call there a lot, why not DCL?
I have always wanted to see Galveston. I looked at it on Google Earth. The port looks really old.
Before the 'Great Hurricane of 1900' Galveston was larger than NOLA. Had many firsts in business and development. The Strand area is very historically preserved and walking distance from ships. They have a big Victorian themed event there every year.
The Cruise Terminal (no.1) is very modern although in the shell of a very old building. They also have the largest terminal gangway in the world. Of course it would be in Texas. When they bring the Oasis of the Seas they will probably do the same improvements to Terminal 2.