No its not the same concept (Which is what the article actually says, despite the click bait title)

Feature flags - roll this out to 1% of users, randomly selected; roll this out to users with X hardware in Y region, etc.

Authorization - only users of the admin role can edit other users

As a concrete example, you might authorize some cohort of users as admins. Within that cohort you want to vary the UI for your admin app by using a feature flag controlling whether to use the old React app or a new Angular rewrite you are rolling out in tranches.

Conflating these concepts might work in some cases, but doesnt scale. Its like saying pods, services, deployments in k8s are all the same thing just because you haven’t yet seen a use case where the difference matters. Its not hard to imagine a use case where rolling out a feature necessitates tediously duplicating your ACL rules if you’re using ACL to gate rollout of features.