Why does Red Hat Enterprise Linux 6/7 grub config miss to add initrd line for latest kernel upon installation?

Issue

• Why does Red Hat Enterprise Linux 6/7 grub/grub2 config miss to add initrd line for latest kernel upon installation?
• Installed latest kernel whereas the /etc/grub.conf file is missing initrd line for the same in Red Hat Enterprise Linux 6.

[root@rhel6 ~]# grep -v "^#" /boot/grub/grub.conf | egrep 'Red Hat Enterprise Linux Server|initrd'
title Red Hat Enterprise Linux Server (2.6.32-754.18.2.el6.x86_64)
title Red Hat Enterprise Linux Server (2.6.32-754.11.1.el6.x86_64)
    initrd /initramfs-2.6.32-754.11.1.el6.x86_64.img

• Installed latest kernel whereas the /etc/grub2.cfg file is missing initrd16 line for the same in Red Hat Enterprise Linux 7.

[root@rhel7 ~]# grep -v "^#" /boot/grub2/grub.cfg | egrep 'Red Hat Enterprise Linux Server|initrd16'
menuentry 'Red Hat Enterprise Linux Server (3.10.0-1062.el7.x86_64) 7.6 (Maipo)' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-1062.el7.x86_64-advanced-0a369e39-a483-4ef3-93b6-7e0ad221c095' {
menuentry 'Red Hat Enterprise Linux Server (3.10.0-957.el7.x86_64) 7.6 (Maipo)' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-957.el7.x86_64-advanced-0a369e39-a483-4ef3-93b6-7e0ad221c095' {
    initrd16 /initramfs-3.10.0-957.el7.x86_64.img