That could be a factor, but if a lot of them work in construction that should actually be helpful in the long term.

It looks like very few new Canadians work in construction:

New immigrants currently constitute only 2.0% of construction workers in the country, and thus more efforts need to be made to facilitate their smooth transition into the Canadian infrastructural market.

I suspect that we'd need a concerted effort to adjust our visa and immigration programs to increase those numbers. AFAIU, the points system rewards white collar credentials. Trades-oriented credentials seem to require Canadian experience in the temporary foreign workers program.