There is a terminology problem here too though. A "patch" should not provide new content. That would be an "update" or an "expansion". Patches are supposed to fix bugs, not add functionality.
I know that's what "patch" should mean, but in practice in the VG industry it has come to mean any free update, linked to a specific product version number, that applies product revisions. Those revisions might just be bug fixes, but can also include new features or changes to existing features/functions. (I've personally experienced MMO patches that removed features.)
I'd prefer "update," but I think we're stuck with "patch."
As for the notion of a "partial NDA," I've been a software dev consultant for more years than I'm willing to admit here. I've signed (and required others to sign) dozens of NDA's, and I've never heard of such a thing, so I call BS.
I've criticized BioWare for many things over the years, but they are doing this right and I applaud them for it. What difference does it make that you've never heard of it being done before for a patch? It's great that they are directly involving users in their development process (something new for them, BTW), and if they feel in so doing that they need to apply an NDA to protect their IP or reserve their right to change the content of the final release, that's their decision to make, not yours.
Is their silence here frustrating? Yes, but -- God -- given what I see here sometimes, I can sure understand it. Do I wish they'd at least publish a "Known Issues" list? Definitely, but what we do know about the contents of this patch tells me they read every stinkin' post, which is more than I would do.