There is a rollout plan in progress(?!) but the only community consensus on it was quite opposed to default-on deployment.
Perhaps this was unclear because the close was written as "No Consensus" (to enable) rather than "Consensus against". This is not unusual when the effect is expected to be essentially the same. Often language like "no consensus (for a proposal)" is used to more openly invite a new discussion, if anyone feels it may lead to a different result. (Either because changes have been made, or because circumstances have changed, or because someone wants to bring new information or arguments to the table, or becomes someone simply thinks that views on the subject may have shifted over time.)
The WMF may be able to (cautiously) go forwards with a project in a genuine non-consensus situation, where the results were close and other factors might support it. However in this case the closer cited a fuzzy&incomplete vote ratio of about 3-to-1 against, and the closer noted that factors other than raw vote count don't lean in the support direction. My generous/optimistic interpretation would put the result at about 2-to-1 opposed. This is important, the RFC topic was "Proposal: Enable Hovercards by default" and there was "no consensus" to take that action. However imagine we rewrote the RFC question as "Proposal: Disable Hovercards". Imagine everyone responded the same way they did the first time. That same 2-to-1 result would pretty well constitute a consensus to disable. Therefore the "No consensus to enable" is effectively a "Consensus against enabling". It was just phrased to be more friendly if you want to try raising the topic again. (Or maybe the closer always uses "no consensus" language to summarize any failed proposal.)
I didn't participate in that RFC, but I'd like to offer my experience with Hovercards. It sounds like a great idea, and I actively tried to help the project along. I hate how often the WMF&community get into conflict and I really wanted to help a project succeed. I enabled Hovercards and played with it, and it seemed great and useful. "Neat, I can get a preview whenever I want". Then I stopped playing with it and when back to normal. Over the next few days it became clear that I was never actually using Hovercards. In fact it became increasingly annoying to have unwanted popups randomly blocking my ability to read the current page. The longer I left Hovercards enabled, the more frustrating it became to have my view repeatedly and randomly blocked by popups. Hovercards are a great idea in theory - you get preview when you want it. In practice, for me at least, ~100% of the popups turned out to be unwanted and frustrating.
Hovercards are a love-it or hate-it feature. I know your survey got pretty positive numbers, but I have to wonder if some of that positive feedback was like mine... that Hovercards only seem great on first impression when you're actively playing with it. Even if a majority of people do like Hovercards, even if you try to make them easy to disable, I think too many people will get pissed off. This is especially critical for logged out users. They'll get really pissed off repeatedly trying to shut off Hovercards every week or every month or whatever. If there is another RFC then I'll have to regretfully oppose any enabled-by-default.