I could be wrong, but I believe the person to whom you replied was indicating that they would be okay with “enshittification” being the word of the century, because there are SO MANY worse things on the horizon or actively festering and spiraling out of control that, if “enshittification” is the worst thing to happen this century, that would be an acceptable outcome. I believe they were using “sign for” as in “to accept, as of a package or parcel”