I read about it a few years ago when leaders of these separatist groups met with Trump administration officials in Washington, D.C. I also doubt if they will achieve their aim of having a referendum.
In countries where a state wants to separate from the current governnet it, it is caused by insecurity and resource management. If a state has rich resources that benefit the country, and it turns out that the state lacks amenities despite its richness, it becomes a problem. And if that state is lacking good security, it is also a problem. It is not always about more money, most of the time, it is about what they are benefiting from the government, which is their right.
The vast majority of Canadian oil and gas is produced in Alberta, where the energy sector is a significant employer and oil and gas tax revenues contribute substantially to provincial government coffers.
This might be one of the reasons.