sys-process/fcron-3.2.1-r1 should provide /usr/bin/crontab as symlink to /usr/bin/fcrontab for compatibility reasons. Looks like the symlinking lost after bumping from sys-process/fcron-3.1.2 Many provisioning systems (ie salt) rely on /usr/bin/crontab to manage cron tasks
This symlink is installed when USE=system-crontab (which is enabled by default)