This is partially correct.... their is a serious issue filling rural teaching jobs (and many other types of jobs in rural communities) because modern day society people do not want to live in the middle of nowhere and would rather be close to the big city. Good luck finding anyone wanting to teach (or nurse or many other jobs) out on reserves due to serious safety concerns.
In Winnipeg they have plethora of young teaching candidates to fill out positions, almost an over saturation making it difficult for young folks to find good full time teaching jobs out of school. The issue is that some school divisions are cutting so much as well as political issues and really making the job less desireable to a point that the older teachers simply do not want to come back. It is not because of a lack of candidates... the issue is cut backs and terrible management at least in Winnipeg. Lots of young teachers are moving out East because they don't want to sub for 3-5 years before getting full time employment here.