Deleted Hey Karl- Microsoft Ignite is expected in the October-November timeframe, and that's when the Package Manager-Intune integration is expected to GA.
Re: the new Store experience not allowing business account login, that's 100% unrelated to Store for Business. I'm not on the "consumer" Store team so I can't answer why they removed the Private tab from the Store app, but it's for sure worth noting in the Feedback Hub or the Store app (Help > Send Feedback). Customers can still spin up Store for Business tenants, though, and sync with Intune - if there's even a single app that they need (Citrix Workspace), it's worth doing. It's minimal time and effort to get it set up. Then once the Windows Package Manager integration is complete, they can start deploying that app via Package Manager and Intune.
Re: Apps being removed from the Store for Business: if it was a paid app (it costs more than "Free"), developers were required to either change the price to "Free" or remove the app. If it was a free app, the developer may have chosen to remove it.