Now, it appears Microsoft is deprecating the Project Osaka app before it ever actually launched. A message from earlier this week for those in the private Osaka preview says:
"Beginning today, we're winding down Project Osaka and it will be fully retired on March 31st, 2017. We understand that this transition won't be an easy one and we're working hard to make this process as easy as possible. Please see the instructions for migrating your data. We've enjoyed working with each of you and we have deep admiration for the things you've built. Thank you for using Project Osaka."
I asked Microsoft for more information on what Project Osaka users should do and whether there's an official successor to this app. No word back so far.
Update (February 6). Here's Microsoft's statement on Osaka from a spokesperson:
"CollabDB was renamed Project Osaka and is therefore the same project. Microsoft is always working on new experiences for our customers, some of which do not graduate beyond the experimental stage. In this instance, the teams decided to absorb the learnings from their work and carry that information forward to their next projects. All customers who were part of Project Osaka were contacted with instructions to ensure the transition process is as easy as possible prior to the retirement of the experiment on March 31st."