Variety's got a little rundown of what to expect from Marvel at this year's SDCC, and buried within that post is the following paragraph...
"Kevin Feige is expected to unveil brand-new franchise starters at the convention in late July. Chief among them is The Eternals, a series about godlike alien beings to be adapted by indie director Chloé Zhao (The Rider) and starring Angelina Jolie, Kumail Nanjiani, Richard Madden and Stranger Things lead Millie Bobby Brown."
...which would seem to confrm something new: Millie Bobby Brown (who recently starred in Mike Dougherty's Godzilla: King of The Monsters and can currently be seen in the third season of Netflix's Stranger Things) is joining the cast of The Eternals.
Variety makes no further mention of Brown's role in the post, which means...well, it means the above is all we have to work with at this point.
A curious move, to say the least! Stranger Things is a great big deal right now, and one would think that the casting of one of its biggest stars in a major Marvel movie would be worthy of its own announcement. Was this a surprise that was intended to be kept unspoiled for the SDCC crowd? Was this already announced and literally everyone at BMD somehow missed it? Was Brown's name included accidentally? We have no idea, but the post has been live for a while (and, indeed, aggregated by several geek-friendly sites, such as the one you're reading right now), so if the information were inaccurate, we assume a retraction or correction would have been made.
Anyway, weird that this is how we're finding out, but there you are: sounds like Eleven's coming to The Eternals, and we'll probably be hearing more about that project when SDCC kicks off late next week. Stay tuned for that coverage, and sound off below if you've got anything to add here.