Boundary conditions
If only a round conformal structure is tenable, this is consistent with Hawking's previous suggestion that "the boundary condition of the universe is that it has no boundary".
But how can the “end of the world brane”, as a boundary condition, then be anything other than an undistinguished point in spacetime, in the same way that the beginning was famously depicted in "The Universe in a Nutshell"?
The trouble with this sort of thing is that the imaginary aspect of Time appears in the equations of both relativity and QM but we have no idea how to interpret that as an aspect of actual reality. As Einstein observed, physicists tend to make bad philosophers.