From the linked abstract (https://pubmed.ncbi.nlm.nih.gov/32958901/):

> In response to the policy, smokers switched from more expensive to cheaper cigarettes and reduced their overall tobacco expenditure and expenditure intensity. However, as smoking became less costly, smokers consumed more cigarettes.

And yes, even if that's true, it's separate from the question of how effective it was as stopping nonsmokers from starting.