Basically what it means is:
NOTE:
Customers do have an option to purchase an 'Extended Support' for EOS products though. If interested, we advise customers to work with their local Broadcom Account team to get all the details.
Also, you can see release and end-of-support dates by product, at Release and Support Lifecycle Dates:
https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/release-announcements/Release-and-Support-Lifecycle-Dates/1911