I downloaded and installed the latest nightly build, and here's my findings:
- Tracking was not affected on my test site, which uses the latest version of the Analytics AppMeasurement library and Experience Cloud ID service.
- Tracking was blocked when I opened a private browsing window.
- When I opened Firefox tracking protection settings, by default it was set to private browsing only. When I changed it to say always, Analytics tracking was blocked.
- Going to a site with first-party image request CNAME redirects, tracking still worked, even with tracking protection enabled.
When Adobe Analytics was blocked, it showed this in the console:
The resource at “http://assets.adobedtm.com/launch-xxxxxxxxxxxxxxxxxxxxxx.min.js” was blocked because content blocking is enabled.[Learn More]
Loading failed for the <script> with source “http://assets.adobedtm.com/launch-xxxxxxxxxxxxxxxxxxxxxx.min.js”.
Following the linked article, it says this tracking protection in private windows has been around since version 42, so since 2015. I'm guessing the 'always' option is new, however it's not enabled by default.
If you're concerned that Mozilla will switch tracking protection to 'always' by default, an option would be to ensure you're using a first-party implementation via CNAME redirects. However, given the number of sites that have dependencies on tracking libraries, the likelihood of this happening is pretty slim in my opinion.