I believe, and I could be wrong here, that previously IFTTT simply consumed public APIs to cobble things together. They are now asking services that want to be

I believe, and I could be wrong here, that previously IFTTT simply consumed public APIs to cobble things together. They are now asking services that want to be IFTTT-able to expose an API that IFTTT defines. IFTTT will still be hitting endpoints on the developer's product's site, but the endpoints are defined by IFTTT and not public.