Thank you.
I think this is going a bit far, trying to control what a committee can or can't do. Committees are essentially their own bosses, as is Parliament collectively, and from time to time a committee may decide to do something. If Parliament wants to limit the terms of reference of the committee to certain things, then Parliament can do that collectively.
I don't believe this should be a rule. We can visit this issue from time to time if some members feel that some bill should take priority over everything else.