DE 12.0.2 is supported in both AWS and Azure:
12.0.02 - CA Workload Automation DE - 12.0 - CA Technologies Documentation
But it depends on what type of cloud services you are buying from AWS. If you are purchasing Infrastructure as a Service (IaaS), then you basically get server boxes from Amazon and you install your DE server or DE agents and pay for it as per your existing licensing agreement. It's really just another virtual server that happens to exist in someone else's infrastructure.
If you are talking about Platform as a Service (PaaS) then there is no way to install DE unless CA specifically releases a version for AWS that would then be sold through the AWS Marketplace and be subject to its own licensing terms. I have no idea if CA has any plans to do this.
If you are trying to schedule things in PaaS, that would likely be done through a web service job, or some other means of making a web service call into PaaS. Most PaaS functions are available, or can be made available as web services.
All of this of course is just my perspective.