There are two separate programs for engaging with Esri staff and software prior to final release. The earliest form of engagement, which is usually alpha or early beta releases, is Holistic Testing Program for Esri Software Development:
The Holistic Testing Program consists of a select user group designed to test Esri software releases using real-world workflows and datasets. By implementing user workflows as an integral part of Esri's software testing strategy, software issues can be identified early on and fixed prior to releasing the final product. Throughout this process, Esri will gain knowledge and understanding of current GIS user workflows and scenarios. The Holistic Testing Program is an opportunity for Esri users to be involved early on with software development to ensure that the needs of fellow customers are met.
The other program, which is already mentioned here and is usually late beta releases or pre-releases, is Early Adopter Community | Esri Early Adopter Program:
This community represents a wide range of experience levels, environments, industries, security needs, and workflows. By joining our Early Adopter Community, you can have exclusive access to early release versions of Esri software. As a member of Esri’s Early Adopter Community, you will have the opportunity to interact with Esri’s development, product teams, and other like-minded community members. We are eager to hear your feedback on our early releases. You can share product feedback, contribute ideas and enhancement requests, and share thoughts and workflow questions on specific product forums within the Early Adopter Community.
Although each program's website makes it seem as simply as filling out a form and signing up, it isn't necessarily that simple. For some products, getting involved is as simple as asking, for others you really have to put forward a compelling case for why you should be included. For a couple products, it took years before the Holistic Testing doors were opened to me, so asking isn't necessarily a sure bet it will happen, at least not right away.
Whether Holistic Testing or Early Adopter, I have never gotten the impression there is a singular Esri point-of-contact that coordinates everything happening within/under the "program." Different product teams utilize the programs to different extents, including not participating at all.
I highly recommend you reach out to your Esri account team or person and inquire about joining a specific program for a specific product. I also strongly suggest you put together a business case, or at least documentation, that covers workflows that are specific and important for your organization and explain why you need to test the new versions prior to release.
