I saw a discussion on HackerNews where one person claimed a rebrand is "almost always a sign of distress", which seems far more speculative than informative. I tried looking it up, and while distress might be one possibility, it's only one of many. Some companies might think their logo is outdated, and choose to update it. That might be especially true for tech companies, where style changes rapidly.

Another possibility I saw was that companies will change branding when they are trying to change direction. Apparently the Steve Teixeira layoff was actually more about AI and Mozilla Social than I had anticipated (he was pushing against AI, apparently, and mozilla.social was his baby), so this might coincide with a full embrace of AI or some other change.

ETA:

Mozilla is using a mix of saturated green, pink, and orange (with the latter acting as a subtle nod to the popular Firefox browser) to inject a pop of color against a white or black base.

Does anybody see pink or orange? All I see are black, white, and shades of green.

I tried to look up the Mozilla Foundation page announcing this, but it looks like they just gave interviews announcing the change. Phrases like "activist spirit," "grassroots to government," "tech with a cause" (paywall), and the perennial "reclaim the internet" ring a little hollow now.

One more tidbit: the previous Mozilla logo was sort of crowdsourced, Mozilla called it "our logo journey". This one, by comparison, was between Mozilla and the agency that commissioned.