From what I gather, they will eliminate all tracking cookies every 24hs. I highly suspect this will also affect any Adobe cookie, regardless if they are first-party or third-party.
"When you first visit a redirect tracker it can store a unique identifier in its cookies. Any redirects to that tracker during the 24 hour window will be able to associate tracking data with that same identifying cookie. However, once ETP 2.0’s cookie clearing runs, the identifying cookies will be deleted from Firefox and you’ll look like a fresh user the next time you visit the tracker."
It's not clear to me if this only affects "redirects" as they call or it will scan for all known tracking cookies and eliminate them. I'm also unsure if the data layer acts as a redirect.
I think the focus on this particular update is redirect trackers. If you look toward the bottom of the article, you'll see the following paragraph:
This only applies to known trackers; cookies from non-tracking sites are unaffected. Sometimes trackers do more than just track; trackers may also offer services you engage with, such as a search engine or social network. If Firefox cleared cookies for these services we’d end up logging you out of your email or social network every day. To prevent this, we provide a 45 day exception for any trackers that you’ve interacted with directly, so that you can continue to have a good experience on their websites. This means that the sites you visit and interact with regularly will continue to work as expected, while the invisible “redirect” trackers will have their storage regularly cleared. A detailed technical description of our protections is available on MDN.
Some of the key points there:
It applies only to known trackers as defined and maintained by Disconnect
The 45 day exception for "any trackers that you've interacted with directly" seems to point to some level of comfort around Adobe Analytics, but more on that below
The focus is on "redirect trackers" (where, as the article describes, includes those extra hops in the navigation process after clicking on a link from a third-party to your site) and clearing storage related to them every 24 hours
For Adobe Analytics, Disconnect has various Adobe domains and endpoints classified in ways that already result in blocked tracking today. I would encourage you to take a look at the links below to understand more about what Mozilla/Firefox considers a "tracker" and whether or not a domain/resource is blocked: