This is fixed-ish. The new build will work but you if you don't have a working app or the link to download it, you can't get the new version. That's pretty problematic since the only way some people could get it to work is for me to email out the link and I don't want to send the link to the whole beta tester pool considering how few of the testers are still active. I'm going to start evaluating Test Flight as a new distribution channel next week.
So what happened? The provisioning profile used to sign the apps expired. This produced the "no longer available" message on run and the failure to install on download. I expected an expired certificate to break a download but not break an installed app.