Using containers for such computation nodes makes a lot of sense, and it would offer other advantages, too. But it's not a silver bullet. You'd still have to work at it.
To really answer your question I need to know how you're deploying your system (is it with an ASG? manually? with some tool, like Ansible?).
If you're using an ASG, dockerizing it wouldn't solve the problem of having to update the AMI. It would still need to be updated, since the launch-configuration refers to it, and the ASG will spin up "old" versions. of course, you can make your ASG instances smarter, by using Chef or something equivalent and let them provision themselves and fetch the latest version of what they're supposed to be running. But that means investing in this extra infrastructure, if you don't already have it; and it also means increased scaling latency, since it takes time to do this self-update when a new instance is spun up.
If you're not using an ASG, you can just push the latest image onto your instances when you deploy. Here a dockerized solution would indeed be pretty handy. e.g. if you join your instances into a Docker swarm, you can deploy a new version with one instruction and it'll be done with a rolling upgrade, etc.
So, as you can see, there are a bunch of ways to do it. Depends on what you're already doing now and what your needs are.