Comment 5 for bug 1611740

grub legacy support is indeed removed from grub-installer now (see above upload comment).

However, grub is apparently still required when building new AMI instances for EC2. I think it probably best not be removed until we can ascertain its use. I've asked the CPC team already.

According to the AWS docs:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/create-instance-store-ami.html
grub-legacy is still used to build images. I've used an approximation of that logic to try to make a new AMI, and it looks like things still work without it, except that the status monitoring then fails for the instance.