Is there any way to have something run for all tags? For example, ec2_facts should always be run when working with hosts in AWS even if you want to use a tag to limit the tasks that you are running.
Nope, there’s no magic “all” right now. There is already a suggestion for this though (and maybe a pull request).
One option is to tag such steps with “common” and always include common.
Aha. Thanks for being the magic index of all open issues 
https://github.com/ansible/ansible/pull/7039 for anyone wondering.