To me when Apple gives users a choice to either use HFS+ (extended) or AFS this indicates to me Apple is thinking ahead and if a 3rd party application maker wants to alienate users by being stubborn and sticking to the old system, they don't deserve support and will lose money. Alternatively they could have two versions which each support either the previous or new file system. I personally believe no more apps should be 32 bit and should all be natively 64 bit as well.
I wholeheartedly agree. Its not easy to drag consumers kicking and screaming into the 21st Century but Apple does a good job of modernizing our experience. Having worked as an engineer for several the computer manufacturers, I can tell you that we suffer through massive debates about moving software or even hardware forward, knowing that here will always be haters that complain about change, but we also know that without that forward push we would have been stuck with 1980s technology forever.
Apple does an excellent job of notifying third party software developers of future changes, years in advance, so they know to be prepared for the transition. This has happened many times but the consumer is unaware of it because its mostly under-the-hood changes, APFS is a massive change so it will be interesting to see how the public deals with the change.
I suspect that all new machines will soon come formatted only in APFS, but that the OS itself will retain support for HFS+ Journaled for a very long time. I can also see that at some point Apple wil turn off support for HFS altogether and probably force users who really need it, to download a plug-in or tick a box in System Preferences to reactivate it
Anyone remember Rosetta? Wikipedia states "Rosetta was a dynamic binary translator for Mac OS X that allowed many PowerPC applications to run on certain Intel-based Macintosh computers without modification". It worked very well, allowed many users to run PowerPC software without even realizing that any translation was going on and yes the haters attacked Apple for having it then on the other side, when Rosetta was finally dropped, a new set of haters attacked Apple for dropping it. Such is the life for computer companies when they bring new software to market.
There are so many HFS volumes out there that I suspect and hope tat support for it will last for decades, or at least for years. LOL