In some cases where user added the premium connector and removed it, after removing the premium connector, the license designation shows as Premium, however only standard connectors are present in that Application.
I would like to see a feature added to the platform where this is automatically updated. The manual process of exporting the app and editing the premium references in the JSON file is very cumbersome and not an ideal way to operate. Reverting to a previous version of the app is sometime not an option if a large number of changes have been made in between the point the premium feature was added or removed. Having the Power App designation automatically updated would make the experience much better.