Glock lists the G48 barrel length as 106mm, so the confusion involves conversion between metric and imperial, and rounding of the numbers behind the decimal point. So the G48 will be legal in Canada without any barrel change.
With respect to the magazine compatibility, my lightbulb went off this morning. Time will tell if it is 100w or just a fizzle, but I think within a year, Glock will announce a new G43 with a wider frame to accommodate the wider 10rd magazine, plus a flush fit 8rd magazine. Since I'm now trying to channel their corporate decisions, they may or may not discontinue production of the slimmer 6rd gun. I'll let you know when I make up their corporate mind.