I don't know that posting every change is important and I don't think that's what anyone was asking for especially not in the forums but having some idea of what to expect and plan for is important for your users especially the ones running client sites with the Framework. A few reasons for keeping your customers updated are....
Because Pagelines has pulled the rug out from under it's customers before (Pagelines to DMS) and needs to rebuild customer faith in the product. In reviews of your product there are some pretty harsh responses from burned users. Major revisions make customers nervous in general and with Pagelines track record in not supporting previous features even more so.
Like @barkingsheltie† mentioned, your competitors are keeping their clients informed it's just what businesses do because it makes sense. If customers don't hear from a business they believe it's stagnating, having financial issues, doesn't care, is poorly managed or a combination of.
Pagelines has left some pretty significant bugs unaddressed for many, many months (my personal annoyance was the broken parallax for others I think probably disappearing content as it's mentioned often in the forums, Post Pins duplicating content raises it's head occasionally). Customers want to know these issues are being addressed and when, especially since in other Frameworks/themes disappearing content isn't normal and if parallax is a feature it usually works.
With DMS some of the Pagelines developers pulled out of the store, it didn't take too much thought to know there was probably some issues that arose that weren't cleared up well. Again made customers nervous.
Any good business realizes it's the customers that keep them in business.
As developers you have to understand that your customers are building and running client sites off your Framework and those sites need to be reliable. Having no updates from the developer, the Pagelines homepage not working in Firefox for Mac (mentioned this two days ago in forum and it still isn't working), the Headlines and Viewer theme Demos not working in your store (again mentioned in forum a day or so ago and still not fixed) all make the Pagelines team look like they don't know what they are doing. Having your homepage not working or parts of your site significantly broken aren't things most clients would tolerate.
Clearly there are a number of designer/developers that want to see this Framework be successful, make us/them happy and your customer base will grow or at the very lest be faithful and set new clients up on it either under their own plan or a personal or business plan. I know Headway and Genesis are often the favorites of many but I personally just didn't enjoy Headway and Genesis takes more time. To customize DMS it takes some CSS for certain but that's one of it's strengths is that it's not so weighed down with base options but can be extremely customized.
It looks like v1.2 is going to offer some great new features and fixes. I'd love to move sites over to DMS and build new client sites with it but it has to be reliable. I know the DMS launch disaster probably set everyone back more than a few weeks and I think most of your customers felt bad for Pagelines but also a little concerned over technical skill considering it took so long for the recovery. There was so much hype over the DMS launch and none over v1.2...odd.
Reliable is the keyword. Reliable product and reliable, routine communication.