If I understand your question clearly. As a visitor in 2016, passport was stamped on entry. While in 2018 wasn't stamp. Yes, it is possible. There are new self check-in kiosk in some international airports in Canada. If you came in through any of those, your passport will be e-stamp not physical. However, if on the same spot you need a stamp on the passport, you need to approach a BSO of CBSA to do that.