The error in your post is an AWS error. Are you getting this when you open a browser window and type in the IP of the instance? If so this means that something in the AWS infrastructure is blocking the access. I would check that your VPC, Subnets, Internet gateway, and Route tables are setup to allow your IP through all of those. Also, check that your Ec2 instance has a Public IP. In the documentation you provided this verbiage was in there:
Auto-assign public IP: This depends very much on the setup, by default a new VPC will not have VPN connections or NAT Gateways available, so in order for Matillion ETL to connect to the internet and for you to access Matillion this will normally need to be set to Enable.
There are a lot of variables at play and these situations are hard to troubleshoot without some extensive troubleshooting, knowledge of your AWS instance. If this doesn't help, it's probably worth reaching out to support so you can walk through the process you went through get the instance created. Hopefully this helps in some way.
Thank you @Bryan for the reply. I managed to deploy at the end, not sure what was the problem. I recreated VPC and it's components and choose different machine image then in previous steps. And it worked.