Original-recipe "root beers" and "sarsaparillas" used to contain sassafras oil; and it was the sassafras oil that lent them a lot of their unique flavor (and "uplifting quality" as a patent medicine, in an era when cocaine was a thing you'd find in a soda.)
The modern interpretations of both drinks, though—even from indie brewers going for authenticity—always exclude the sassafras oil. Much to the detriment of the flavor-profile of the drink: they're like decaf coffee with no replacement bitterant!
I always assumed that sassafras oil had just become a controlled substance in most countries. But maybe it was just the US where it's controlled, and nobody had been bothering to try to brew "authentic original-recipe root beer/sarsaparilla" anywhere else until now? (It would make sense, seeing as those drinks weren't really a thing anywhere other than North America, and so it's only really the US and Canada where people would show much interest.)
Good on this brewer for having enough faith in the Canadian indie beer market to brew something that very likely can't be exported to the US. Maybe it'll draw some US tourists to come north to try it, though!