Please! Your interpretation of "I'll keep you in suspense" only makes sense if you strip the context. The question of concession was only asked because, he's been claiming the election is rigged. So that question of concession, translated to include the context, was,

"Ok Donald, are you really going to claim to the nation that the elections are rigged, and that you won't accept their results?"

And his, answer was, "We'll see." Which means, yes! He's standing by the claim. So don't equivocate Trump's position. It's not media sensationalism.