There has been some confusion (myself included) on what is vulnerable to this bug and what isn't. Some folks can replicate and some cannot - so I think its high time to test this properly to see what versions and scenarios are affected by this bug.
The table below is sorted by macOS version - I'm just testing 10.13.x here. (If you happen to get it to leak the password on 10.12.x please let me know.) I'm also organizing by disk formatting scenario since I believe this is where most of the confusion comes from.
APFS encrypted volumes can be created on the disk level as well as the volume level and it truly seems to make a difference. Please also test if you find (or don't find) the results in the Unified logs and/or the install.log or neither (and god forbid any other locations you might come across!). I'm also consistently using the "Erase" button versus the "Partition" button.
If I am missing a certain scenario that you think should be added please let me know. If you disagree with the current findings - also let me know (I will also expect screenshots/videos from you to be sure we're on the same page.) I have tested 10.3.3 (host system) and 10.13.4 (VM) but would love someone to sanity check me - I've been wrong in the past!) I would have done more testing on different versions but have a limited set of systems as I'm traveling right now.
I will update the spreadsheet below as necessary.