You are looking for end-of-life and product lifecycle information for Edge Secure Web Gateway (formerly ProxySG) or Advanced Secure Gateway (ASG) devices and software.
For a complete list, see End of life and product lifecycle information for Broadcom, CA, and Symantec products.
The attached PDF identifies key dates for platforms and software that have reached end-of-maintenance or end-of-life in their product lifecycle (these are listed by model/version number).