What that means is right now, in the pre-release versions of APFS included in 10.12.x, those things do not work. Filevault becomes unnecessary with APFS as APFS has its own encryption. It remains to be seen whether that functionality appears when APFS becomes the default in macOS. It may be that devices with Fusion Drives will need to continue using the existing HFS+ filesystem. I would imagine that Time Machine will be modified to work in some fashion by the time APFS is the default.
Basically, the apps need to handle unicode themselves. The key here is to handle unicode names in a consistent manner. Devs who use high-level filesystem frameworks are most likely on the safe side. If an app does not care about this at all, you can end up with two files that essentially have the same name. I doubt that this will cause a HUGE mess, but there is a potential for at least SOME mess."software that didn't follow best practices" would you explain what you mean? Thanks.
No, Apple is mainly delegating this task to storage device firmware. Read the official FAQ: https://developer.apple.com/library...f/doc/uid/TP40016999-CH6-DontLinkElementID_16Also, will APFS also help against data corruption, bit errors, and bit rot?
App access the drive by way of APIs so at that level nothing will be different and there shouldn't be any issues. Utilities will be the one area that will have issues and require an update to work, since they tend to access the storage device at a lower level.6mos to a year. I wonder what apps will be trashed?