Updated to the latest version of Firefox and it asked me if I wanted to try their new anti cookie feature with stops all tracking. How will this affect tracking links?
This has no effect on simple affiliate links because they don't set cookies until a user clicks and goes to the target site. Note externally hosted banner ads may set a third party cookie, but they aren't used much anymore. What happens then depends on how the target site sets cookies.
If the target site sets a cookie using their own domain then nothing will be blocked.
eg: you refer to ww.targetsite.com and the cookie is configured with the domain targetsite.com
If the target site sets a cookie from another third party domain (a.k.a. cross-site cookie), it could then be blocked by browsers set to strict cookie blocking modes.
eg: you refer to ww.targetsite.com and the cookie is configured with another domain such as targetsitetracker.com
None of this is new though. People have been able to set their cookie blocking to strict modes like this for decades if they knew how to change the browser settings.