I'm not going to comment on the admissibility of this proposal, but I can certainly make some observations about its impact.
Under this section, the provinces bound to the federal government under an agreement that provides for funding would be considered agents of the federal government, in a sense. Normally, by which I mean without this amendment, that is not the case in law. For a province to be considered an agent of the federal government, something more than the provision of funding is required.
If, for example, there were an agreement or an accord between the federal government and a province or territory, it might well be that this province or territory would continue to exercise powers within its areas of jurisdiction, such as health. Simply providing funding and making the provinces indirectly responsible for applying the Official Languages Act may not be an infringement of the sharing of jurisdictions, but it does raise some questions because it's certainly a stretch. It goes beyond the jurisprudence. The Federal Court has ruled on this matter, in Lavigne v. Canada for example, and the Federal Court of Appeal also handed down a decision in 2022. It would therefore be beyond what is normally admitted as the role of an agent. It requires more than a mere funding agreement between the federal government and a provincial government.
It would therefore have several impacts on how things have to be done, and on the provinces' exercise of their own powers and responsibilities under the Constitution.