Hi folks - This was not our intention.
Roku partner support manages adding/removing the apps from their store.
Unfortunately, it seems they went beyond just de-listing the legacy app. We are working with them now to resolve it, if possible.
UPDATE - 6:00 PM ET - Roku partner success has reinstated the legacy Tablo app. It may take 24 hours to return to the Roku App Store. Once it does, those who no longer have the app will be able to download it again.