Using New Outlook on Windows for personal email, calendar, and contact management
For now - my job necessitates that I stick with Classic!
Same here! :-)
There are some "high-profile" features coming in the first half of next year. Some in a "Version 1" state, some a bit more polished. For instance, Read-Only pst-file support for emails is currently planned for March 2025. Read, write, and/or import support and support for other items types (Calendar, Contacts, etc...) will be worked on after that and released as a "Version 2" and maybe even a "Version 3" state before New Outlook becomes Opt-Out and thus basically the recommended version for the majority.
For some, this is a major blocker while in other environments, pst-files have been banned for over a decade already. That's what makes it so hard to determine what gets developed first.
And yes, New Outlook will most definitely get an opt-out feature so you can continue to use Classic Outlook until its final day. However, hopefully by then proper replacements have been added for all your working scenarios and you won't need it.
That's why being able to provide feedback at this stage of the development is so important but rest assured; The Outlook and Exchange MVPs are fighting hard for all the features that really should be kept or, even better, can finally be approved upon since various "Classic" restrictions no longer apply.