Can I use an ELB in AWS GovCloud Instead of NGINX for high availability?

We are seeking to run Mattermost in HA mode in AWS GovCloud. Can we use an Elastic Load Balancer (ELB) in front of the two Mattermost server instances?

Looking at the NGINX reference article on the topic and would still like to have input from experienced users.

Yes you can and we have customers that do. For large load instances it is still advised to run nginx since it will cache and serve up our static files reducing the load on the mattermost application servers.