Achronality of late marginally trapped spheres

Let $\mathcal{A}$ be the set of spherically symmetric marginally trapped spheres, let $v$ be the null coordinate used in the paper, and let $V$ be sufficiently large. Achronality conjecture. For sufficiently large $v$, $\mathcal{A}\cap\{v\geq V\}$ is achronal. The paper presents this as a reasonable conjecture concerning the still-unexplored structure of the set of marginally trapped spheres; no resolution is supplied in the given text.