As mentioned in the other thread, new functionality such as OpenID Connect will only be available through the Access Gateway. You will not be able to use the web agent option pack for this.
Another advantage of the Access Gateway is that it is much easier to install and configure compared to the WAOP. The AG has all the federation components ready to deploy. You just have to tick one box during the install and everything is deployed. Also no need to have a web server with web agent in front of the AG.