SPOILER ALERT: This post contains details about the ending ofJohn Wick: Chapter 4.
In an interview with Collider, Iwanyk discussed the end of the film and the possibility of additional chapters.
Longish story short, Wick seems to expire after the showdown.

Keanu Reeves in ‘John Wick: Chapter 4’Murray Close / Lionsgate / Courtesy Everett Collection
Or at least probably nah.
By the end, hes always like, I cant do this again, and we agree with him.
The guy is just a shell of himself because he just goes off and goes for it.

He was like, I wanna be definitively killed at the end of this movie.
We were like, You know, well leave a 10% little opening.’
Theyll call me and let me know, All right, were showing up.
Heres where you show up, and heres what our story is.'