Will be Instagram login totally deprecated?
What I can say about this, after two months of investigation, is YES, Instagram login will be totally deprecated.
This is not directly said into official news, but official news announced "Instagram API Platform Deprecation" and Instagram login is under that platform, that will be totally deprecated.
Another point is that since some weeks, instagram login is no more working as before due to the error "parameter present into the redirect URL: force_classic_login"
- Is there a way to remove force_classic_login parameter?
- https://github.com/cosenary/Instagram-PHP-API/issues/255/
Seems Instagram is adding this parameter into redirect URL to force "classic login view" and this classic login view is causing issues on some devices due to cookie error management.
Facebook direction is pretty clear: they want to move everything from "user oriented" to "business oriented". So developers now should build apps for companies where they can use Facebook login, along with "Instagram product". So who will use those apps will click on "Facebook login" and during permissions they will be asked to share Instagram scopes. To better understand this flow, see official screencast here: https://developers.facebook.com/docs/instagram-api/getting-started#screencast