*Summons self* Soooo hoi. Wanna clear things up with a lil question: If, "for some plotty-convenient reason", a portal leading to another universe -or even to the multiverse- opened, would The Glitch spread into it? Or would it ignore the portal?
The Glitch is a rift in timespace, and allows the Void to spill out of it and into the world. If a portal to an untainted world were to open, the Void would seek to fill that space as well.
If it helps, imagine Axetale as a container full of water. The water, or the Void, was poured into the top through its opening, or the Glitch, and the new portal is a hole punctured in its bottom.
So, yes. It would spread, to the ruin of all.