I can certainly take an initial stab at that question, and others can add detail.
Yes, there are provincial incorporation statutes companies can also choose if they wish to incorporate. By and large, the CBCA is viewed as the model for a number of pieces of provincial legislation. Often, if changes are made to the CBCA, similar changes are made to provincial statutes. It's not always the case. But it's very much viewed as a fairly effective piece of legislation by the provinces.
It's up to corporations as to where they incorporate, and it's very much a business decision. If a business knows from the start that it's interested in operating across the country, and it wants to know whether a particular business name has been taken across Canada, it might choose to incorporate under the Canadian Business Corporations Act, because that search will be done. Other than that, it's very much a matter of a business decision by the prospective new business.