here is the official statement on the timeline released a few days ago.Not sure about 2016 PGP, but quite sure we were told the whole processing time would be within a year for 2017. (Not sure where I read that). So previous years applications shouldnt really affect 2017 PGP
https://www.canada.ca/en/immigration-refugees-citizenship/news/2018/02/spouses_being_reunitedmorequicklyincanada.html