Certainly. Statistics Canada produces quarterly population estimates. It has been doing that since 1971, and there's a statutory requirement under the Federal-Provincial Fiscal Arrangements Act for Statistics Canada to produce an annual population estimate to allocate funding for the programs the minister referred to.
Basically, it attempts to correct for the census net under-coverage, which the minister referred to, through a series of statistical methods, and then it updates the estimates based on population trends and information from provincial vital statistics and from Citizenship and Immigration.