It's an excellent question.
First of all, I think it's just a good practice. I would expect that an independent officer of Parliament would be preparing work plans. As I've noted, I don't think these things should be approved by the Speakers. I could easily envision cases, even in the current environment, in which the PBO may decide to do investigations on sensitive files leading up to an election. I could see that a Speaker—certainly the Speaker of the House is a political person—might decide that this should not be part of the work plan and would not approve it.
I am also quite aware that some of my colleagues in the Department of Finance don't like the fact that the parliamentary budget officer produces independent economic and fiscal projections, and they could put pressure on the Speakers to take this out of the work plan. You could already see in the language of the legislation that there seems to be a willingness not to want the parliamentary budget officer to do proactive work. I think you want a parliamentary budget officer to do this type of work, not wait for MPs to say, “We need to look at this” in order to provide this analysis to MPs and to Canadians.
I think, then, it would be potentially very restrictive, if the Speaker were responsible for signing off.