If you have a different /usr partition rc.sysinit fails to set the correct keymap since the keymaps and layouts are in /usr and it's mounted after the setting of the keymap.
yes, but the keymap will still be loaded by the keytable initscript later in the boot process, just as it was in 5.2. The loading in rc.sysinit is for people that put the keymap in /etc/sysconfig/console, so that they have the keymap loaded if they need to login (fsck problems, etc.)