It's a little surprising - even as a Canadian - if you're unfamiliar with Canadian politics/history/civics, but Canada is more loosely held together than most other countries, including the US. And a comparison with the US is instructive, because Canada's founders were unifying the country the wake of the US Civil War and were working very much in response to it: there was a fear that the US would turn imperial in an exercise of national unity and begin trying to snatch up the rest of the continent from the British and a belief that the British wouldn't care to defend them, which was arguably the primary motivation for Confederation: to form a unified front against American expansionism. And the Fathers of Confederation had seen how horrible the Civil War was and wanted to prevent that sort of thing from occurring, so the provinces - like in the US, formerly independent colonies - were given more power than the States, with the separation of powers clearly and rigidly defined.
The Clarity Act itself wasn't part of Confederation, but that's the cultural legacy that informs it: a civilized process allowing provinces to separate without bloodshed is just about as fundamentally Canadian as anything.
So it can be argued that the Clarity Act is a way to legislate friction to defederation.
Of course Quebec (and like Albertan) separatists hold that all this is moot and that they can self-govern as they wish following a referendum. Others look at the "no-deal" Brexit as a template.
If it really came down to it, i think it would be the supreme court that decides.
(Cue the "AB is nothing", "AB has no culture", folks that don't have a clue what they are talking about).
That's also the prevailing sentiment in much of Alberta.
Does there need to be a legal process? If Albertans are willing to fight a war over it then all they need to do is declare that they don't recognize Ottawa's authority anymore and then go about trying to get other countries to recognize their independence.