For that matter, has ANY modern church president made that claim?
When Joseph F. Smith testified under oath before the United States Senate and was asked if he was a prophet of God he responded, "I have been so sustained." When Hinckley was on 60 Minutes and Mike Wallace asked him, "Are you a prophet of God?," he responded with the same answer, "I have been so sustained." Those are evasive answers. Being sustained by the members is not what makes one a prophet. God is what makes one a prophet. If I got a bunch of people to sustain me as a prophet of God, would that make me a prophet of God? Why would they not just answer the question?

Because they know they're not prophets and because they feel stupid saying that before millions on primetime TV!

DeepMind is your new god and AlphaGo is its prophet:

http://www.wired.com/2016/01/in-a-huge-breakthrough-googles-ai-beats-a-top-player-at-the-game-of-go/

What makes a good prophet is one who makes a good profit.

Just like when Horny Joe's prophecies commanded saints to build him a mansion, Tommy has commanded them to go shopping in these latter days.

Maybe it's like when pontus pilot asked jesus if he was the christ and once again there is the evasive answer. It's a sensitive question for some reason.

"I am so sustained" is about as close as they'll ever come...

just sayin'

There are only three possible answers: "No", "Yes" and "I am so sustained".

"No" is truthful, but that truth is not very useful.

"Yes" is a bald-faced lie and they know it, so they avoid saying it.

"I am so sustained" works because they avoid the first two answers while not being accused of lying.

I doubt Mike Wallace gave the Hinckster a list of questions before the interview, but I am willing to bet that the Hinckster formed a team of people to come up with a long list of questions that Mike would probably ask, and that the answers were well-rehearsed in advance. The "I am so sustained" answer is almost a no-brainer in that context.