Firefox

I've only just started looking into this, but I think it's all fluff. The claim is that any sharing of data could be considered a sale.

This article says that an overly generalised definition of "sale" was proposed in California law, but that language was removed before the law came into effect. The CCPA webpage also frequently talks about opting out of "sale or sharing", implying those two are different concepts. Thus Mozilla should be able to share data as needed to perform user-driven functions, while still retaining the pledge not to sell user data.

There could also be more nuance in this. Perhaps Mozilla is concerned about liability based on third party actions - if they share with a 3rd party to perform a service, but that 3rd party doesn't follow the privacy terms, then Mozilla has an increased risk of litigation.

I haven't started digging into the actual law itself yet, but the cynic in me wonders if organisations and their lawyers are looking to use this misunderstood news story as an excuse to weaken the privacy rights language. And the effect here is more significant to the user than the mild reduction in risk for Mozilla.