That would be nice, a modular phone that would be as easy to upgrade as a desktop computer!
Closest we have to that would be the LG G5 (removable battery and modular components), but no where near the FairPhone.
Keep in mind that FairPhone would not be carrier-locked. Although Koodo carries Nexus/Pixel sim-unlocked phones, most sim-unlocked phones never make it to carrier stores.
Not sure whether Koodo would offer it (Telus would have to approve). Sadly, if they only make it multi-sim or if it's easy to "upgrade" the phone to multi-sim, I doubt Canadian carriers would offer it.
Just my 2c.