DEVICE_PACKAGES in initramfs?

Is it expected that packages listed in DEVICE_PACKAGES should be present in the initramfs image as well as the sysupgrade image? The Amped Wireless ALLY devices require a 2-step installation (initramfs then sysupgrade) and depend on uboot-envtools during sysupgrade in order to check & set the boot partition.

When I build images from source, the initramfs image contains uboot-envtools, however the release initramfs images on do not. If DEVICE_PACKAGES isn't it, what's the right way to include extra packages in an initramfs image?