>>96245483
>Destroying the Webway gate would trap the rift in the Webway and prevent it from spilling out.
Or make it impossible to close. Chaos is chaotic and throwing in the psychic power of big E makes the portal alone an unstable unpredictable nuke in of itself saying else is wishful thinking.

It could seal, it could get bigger, you don't know, nobody knows and certainly not the nigger primarch. Here's some things that you should factor in though:
>Emperor is a psyker. The best psyker
>Psykers are impacted by emotions just like the warp and stressing them out makes waves in the immaterium in scale with the ability of the psyker.
>The warp can and does get powerful enough to defy it's own rules like spawning warp portals or dabbing on shitty man-made webway gates that nobody has the ability to maintain in years.
>Nuking terra would kill everyone on it. Killing mass amounts of people causes the warp to churn even more since now there is a spontaneous surplus of souls and deamons trying to eat the souls in that area.

Even if your little webway gate successfully closes with no issues whatsoever. Who cares? You just created several known factors for a great rift 2.0 and another cg.