The major user visible change in this release is that fsck.fat now defaults to interactive repair mode which previously had to be selected with -r. The previous default of a read only check mode was confusing to users who had to repeat a potentially lengthy fsck.fat run with the right option in order to actually fix their file system. It was also pointless – the interactive repair mode already won't write anything without asking for confirmation.
mkfs.fat now allows choosing 0xF0 as the media byte which was previously rejected.
mkfs.fat now supports the --invariant option to facilitate testing mkfs.fat itself. It will reproducibly generate filesystems without random or time based differences between them when all else is identical.
Bugs fixed in fsck.fat are a read one byte beyond the end of an allocated array when checking some FAT12 filesystems, and checking that the first cluster of a file as specified in the directory entry is not 1. Previously it could attempt to follow a block chain starting on cluster 1 and segfault when the conditions are right.