Phrases and concepts run through those conferences every year. I think both definitions contain elements of what makes something a platform. It implies that there's something below that isn't raised. Maybe what's below is very rough and uneven, and the service provided by the platform is something that simplifies or flattens the concepts to make them easier to work with. I think so.
Platforms build on platforms.
Elegant, but a bit of a kludge. Not a political one, but a celebratory party. If I'm the only partygoer, it's not much of a platform. I want dancing, singing, and romancing at my celebrations. It takes more than one to tango.