I don’t entirely understand your question.
Could you rephrase it?
Sure. I think you made the point that the reason changes could be made in the first instance (the change being lets just replace the entire thing with a constitution) is that there was no rule forbidding it. In this case, the constitution expressly says no way to full replacement.
While I would agree thats the case, I don’t think anyone is worried about a full replacement. They are worried of games being played, “repeals” and “interpretations” of things we are being assured would limit and control the process.