Yep, I found about this a few weeks ago when the Dungeon Defenders devs posted about this on their forum because there were so many people complaining about the consoles getting left behind because they had only patched it once.
According to them the first patch is free but the rest of them cost.
Q. What is the difference between patching on Consoles and PC?
A. There are two key differences between patching on consoles and patching on PC: approval processes and platform-restrictions. The former forces content to be finished well in advance of their release on console. The latter includes restrictions such as patch size (4mb on XBLA, unless you’re granted an exception), content, etc. For example, XBLA patches stack, so it would require anyone who downloads Dungeon Defenders to immediately download all of the subsequent patches on launch. So, even if we were allowed to update console like we have on PC, anyone who downloaded Dungeon Defenders today would immediately have to download multiple gigabytes of content via a series of updates, before actually launching the game.