The word “necessary” imposes a high standard. It also raises some debate about what is necessary and what is not. On the other hand, the word “appropriate” leaves room for institutions to manoeuvre, to have the discretion to implement the commitment in spirit, without necessarily forcing them to the point where they have to justify the necessity of each measure.
Evidence of meeting #51 for Official Languages in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was amendment.
A recording is available from Parliament.