After I noticed Firefox has removed the Pocket branding but kept the Pocket stories, I also noticed the settings screen on the homepage no longer lets you disable sponsored stories or links.
Firefox 115:
Firefox 139:
You can still remove these advertisements, but you have to leave the homepage and dig through the settings to find that option.
I'm enjoying Zen, really gets out of your way nicely. Does a bunch of things I used to hack in userChrome.css better, still reasonably secure as best I can tell, it's not librewolf but it's still firefox so I add back the normal privacy add-ons, about:settings etc, but the UX uplift is worth it.
That said, without the firefox base we're all fucked, so this, and their general culture, is really quite disturbing.