Interestingly, while reading that section, I couldn't help thinking EFF was in the right to oppose it. Wanting to restrict what a corporation can mine about you is laudable, but achieving it through a hack such as (in the article's description) "prohibited email providers like Google from reading or otherwise analyzing people’s emails for targeted ads unless they received affirmative opt-in consent from all parties involved in the conversation—a difficult-to-impossible requirement that would have effectively nipped Gmail’s business model in the bud." seems an extremely poorly conceived way to do so. In the real world, that would be the equivalent to requiring you to get permission from anyone that sends you a letter before showing it to someone else. That's an extremely information hostile stance, and would have likely had far-reaching effects the majority of us would consider negative.
If you really want to protect people, you give those people rights, you don't restrict specific types of third parties from performing specific actions, as that's easily circumvented and generally it ends up causing weird negative interpretations later as people try to expand it to new situations it didn't envision and we have case law expanding a restriction instead of legislation (or at worst case law expanding a right).
If what we really desire is that all parties in a correspondence need to agree before it's shared with a third party, we need to specifically legislate that, and not just use it as a shortcut for the intended goal. Something as far reaching as that and possibly conflicting with freedom of speech should not be considered lightly.
Truthfully, that's about par for how biased this article seems to be presenting things. I wouldn't be at all surprised if people found that on researching some of the claims they became more familiar, and they found they did know of them at the time and had a stance, but the presentation here is so foreign to how they remember it that as to be unrecognized when presented in the article.
I'm not going to say the EFF is perfect, or without it's own bias or conflicts, but I would be very suspect of anything you learn about them where the majority of the information is sourced from this article.