I after the upgrade to 4.4 I am no longer seeing API Explorer as a menu option within Publish. I do not see any release notes posted so I cannot confirm whether this is intended or not. Please advise.
Release : 4.4
Component : API Developer Portal
In portal 4.4 API Explorer is only accessible through the API Portal/Ingress tenant (apim.<domainame>). It was replaced with the "SPEC" (SwaggerUI) interface. So if you are using an external tenant, test and explore APIs use the Swagger UI instead. The major difference is that SwaggerUI (Spec) does not have the ability to generate sample code for multiple languages the way API Explorer did. Just generates a curl call.
Please see our doc on Testing and Explore API's.