It would make more sense to tax their income or enterprise in some way rather then attempt some unilateral law to ban . Clearly there is demand and their service is advertising, most countries don’t prosper by restricting parts of an economy with a personal bias.
Actually it depends on how gambling regulations are applied, If it is legal and taxed for everything done then unilaterally banning gambling advertising is not fair enough.
Influencers do create content on demand, if a gambling content ends up becoming a new problem,
then it needs to be reviewed again how gambling regulations will actually be applied, if it is indeed banned everything must be banned, not just unilaterally.
If it becomes an economic sector that concerns many people, then it needs various kinds of considerations before making new restrictions or rules,
this will indeed enter the personal realm and how it affects everyone.