Just an additional thought. I don't know when your app for iOS will be available, but it will probably be too late for my firm. Because we authenticate to office365 with ADFS and on-prem Azure MFA, when a user opens a link to a video, they are presented with the ADFS forms based logon. because of the difficulity with usernames and passwords in that mobile form factor, we have been avoiding its use. when you do make an app, make sure the app has the same authentication integration with Microsoft Authenticator that the other office apps use.
After waiting for an app since GA, we have decided to pursue a different solution for corporate videos.