This was done on a trailling basis for a couple side arch's builders by me and another. It turns out to be a lot of chatter and 'noise', and not much 'signal'
Although it might not be of any real use in indicating when a version would be ready, I think it helps a lot psychologically when people can see that something is being done, even if it's discovering bugs that will push back the release.
A lot of the anxiety seems to be about the silence about any kind of progress. A tweet or post of that nature once a week takes maybe all of 1 minute to send but would reduce a lot of the unpleasant noise I see being tossed up on the forum and lists. I suspect it would be less frustrating for the devs as well by reducing the amount of bitching and offers of help they don't want at this point.