If you take your /usr onto a separate partition (as recommended by the RedHat Linux installation guide), the /sbin/setsysfont couldn't load the default system font and translation table from the unmounted /usr partition.
The setsysfont call is at the beginning for fonts in /etc/sysconfig/console (set up by the installer). This call will be made smarter in the next release of initscripts (> 4.21). setsysfont is also run from the keytable init script, so it should get run later in the install.