First of all, I'd just like to quote from the notes provided by former commissioner John Reid, wherein he addresses your question about possible effects. I'll quote him directly:
Since anyone in the world may make access requests through a Canadian agent (and many do, especially in the immigration field), this change is not expected to significantly increase the number of access requests.
That seems logical.
There may be a marginal increase, because, for instance, researchers will now no longer have to ignore Canada because the system is too complicated and, if they're doing an international survey, decide to include Australia instead.
I think there would be a net benefit. I think it would also help raise Canada's profile internationally, which I think is something that this government is trying to do.