The content interface supports a default-provider attribute holding a snap name. That is the default provider for that interface, meaning that if snapd does not see any other snaps in the local system providing a content interface with the same content label, it will fetch that snap.
The auto-connection rules are still used to define whether to establish that connection or not. In other words, either it needs to be a snap from the same publisher, or the content provider must be a reviewed request that got auto-connections enabled for it.
That constraint exists to improve the stability of the snap ecosystem as a whole, by making sure that either the publisher is the same or that the person publishing a snap with content for everybody is aware of the stability requirements.
None of that is similar to deb or rpm packages.