Theory; what if you let Toriel destroy the exit to The Ruins

During my experience playing UNDERTALE, I went straight past Toriel, not killing her of course, and out of the ruins. Me, being stubborn and curious, didn't let her destroy the exit. My question is what if you stood by and let her destroy the exit to The Ruins. My theory is that if you let Toriel destroy the exit, she'll do one of two things. She'll either not be able do, for an emotional reason, or she will destroy the ruins and you as the player will need to find another way out. Now, we all know that fighting Toriel isn't easy, but she won't kill you. When your HP is low enough to kill you will one hit, Toriel's attacks will be far to the sides. This makes it easy to kill her either on accident or on purpose, if you chose the genocide route. To avoid this, I would try to let her destroy the ruins. If you know what will happen, please tell me in the comments below! And, as always, stay determined my friends!