The "before-header" area has removed in version 3.2.0, from themes that previously contained it.
This was previously promoted as a space to put newsletter signups, or ads.
However, recent changes to search engine algorithms have started penalizing websites that place banner ads above the content, which pushes the content further below-the-fold.
Modern user experience
This makes sense from a user experience perspective: when you first land on a webpage, you want to see the content and receive value before being assaulted with ads (or a newsletter signup).
Modern ad companies automatically place the ads for you in your content using an algorithm, requiring no effort on your part to manually insert ad sections or snippets.
Google is actively penalizing sites that have too little content above the fold.
This also applies to calls-to-action for newsletter signups: If I land on your website and have no idea who you are or if your recipe is good or bad, I have zero interest in giving you my email.
The best place for a newsletter signup is near the main content (eg. the recipe), or at the end - after you've demonstrated that you're not some copy+paste hackjob, and have value to deliver in exchange for submitting my email.
We've removed this section as a best practice.
Can I get it back?
Yes. We don't recommend it, but you're free to do it.
To get it back, edit your functions.php and head to the two sections that have this comment:
/* // removed 20181101 - bad user-experience
Remember to also remove the closing comment tag below each one: