It may be true that this represents a bug in the syslinux package. But from an Ubuntu user experience POV, this is undocumented behavior - I didn't know that hitting 'esc' at that screen did anything, and we have never had a 'text mode interface' as part of the supported UI. The supported interface is the F6 "extra boot options" interface which is being described here as a "workaround".
It may be true that this represents a bug in the syslinux package. But from an Ubuntu user experience POV, this is undocumented behavior - I didn't know that hitting 'esc' at that screen did anything, and we have never had a 'text mode interface' as part of the supported UI. The supported interface is the F6 "extra boot options" interface which is being described here as a "workaround".