Yes, it's unpopular. There've been no polls that indicate it would have any chance of passing if it came down to a vote. A lot of Albertans love to grumble.
The only actual test of separatism in albert has been support for the pension plan and that has been so abysmal they've put the entire push on hold.
Which is why it's important to remember that polls are a moment in time and the circumstances of that moment.
One divisive comment from Carney or his cabinet. One Trump truth. One more set of tariffs. That's all it takes for a 20% swing in polling that already shows that shows that 36% of Albertans are for leaving[1].
Also worth adding that everyone is sleeping on Saskatchewan which is crucially important to Canada, even more ignored by the Liberals than Alberta, and just as likely to leave.
Saskatchewan is also suffering China's tariffs on Canada, which Carney has not ever responded to and ignores almost as much as he ignores Saskatchewan itself[2].
[1] https://angusreid.org/referendum-alberta-saskatchewan-smith-...
[2] https://www.rbc.com/en/thought-leadership/the-trade-hub/food...