As the minister said, the threat is evolving, and the tools need to evolve as well. So yes, absolutely: this would be another tool to improve transparency. But I wouldn't want people to think that this would be the only tool needed.
By requiring people to declare their affiliation publicly, such a registry would effectively increase transparency. It might force people who want to commit these acts of foreign interference to use more resources, which might make it more difficult for them to do so.
So in terms of the ecosystem of foreign interference in Canada, this tool would therefore be useful, but other tools must also be considered.