In AEM 6.3, we could expose our page content as JSON without using Content Fragments or Experience Fragments with the extension caas.json (e.g. localhost:4502/content/we-retail/us/en/men.caas.json) to 3rd party apps.
AEM 6.3 output :
After migrating to AEM 6.5, when we hit the same URL, we receive an error saying - Invalid recursion selector value 'caas'
AEM 6.5 error
In the release notes of AEM 6.5 we did not find any deprecation/removal of this feature.