Avengers 4: An Iron Man 3 Character Is Returning
Could this spell doom for Tony Stark?

The Avengers 4 cast is growing by the day, and surprisingly, the latest addition is a character most MCU fans probably wouldn't have expected to see again.
Thanks to IMDB, we now know that Ty Simpkins is returning, having appeared in Iron Man 3 as young Harley Keener. Talk about unexpected developments.
Back when Iron Man 3 came out, Simpkins was actually the subject of rumours that he'd signed a multi-picture deal, and subsequent rumours suggested he might be about to take over as Iron Man by the end of the Iron Man 4 movie that never actually happened. Let's not jump to conclusions about the latter, as that would be plainly ridiculous.
What's more interesting, in this respect, is how this might fit into the news of a casting call for mourners that was revealed not so long ago (by CBR among others). It feels a little ominous that that would release to the wild just around the same time that a character would reappear out of nowhere for seemingly no reason.
Could Harley be turning up to mourn Tony Stark? That'd be as horribly devastating as it would be entirely fitting, especially as Stark's arc in the MCU would end perfectly with him dying. He's been defined by a burning need to defend his friends and his world and laying down his life to atone for his past mistakes and to protect them would be the best way to write his development.
It might hurt, but that's the truth, and unfortunately, Simpkins returning fits that a little too nicely.