The new age limit of “under 22” will come into effect this fall, on October 24, 2017, raising it from the current “under 19” requirement. That means its only applicable for next year.
https://www.canada.ca/en/immigration-refugees-citizenship/news/2017/05/changes_to_regulationswillseeageincreasedfordependentchild.html?_ga=2.237429696.1168184280.1494351380-186409005.1459544954
https://www.canada.ca/en/immigration-refugees-citizenship/news/2017/05/changes_to_regulationswillseeageincreasedfordependentchild.html?_ga=2.237429696.1168184280.1494351380-186409005.1459544954