Creating a new statutory holiday would go through the same legislative process as amending other pieces of legislation, so it is within the power of the government and the Assembly working together to make something like that happen. No, there are no barriers.
R.J. Simpson on Question 558-19(2): Making a Holiday in February
In the Legislative Assembly on February 12th, 2021. See this statement in context.
See context to find out what was said next.