Warren Buffet is a long-term investor. His net worth is more than double the entire value of the Bitcoin currency combined. It is still way to soon to tell whether his prediction was correct or not.
His vision might be a 20 year vision, and you never know, so don't speak too soon. He could very well still be correct. It could crash at any time. Just because it's had a rise, doesn't mean anything for long-term growth.
If anything, the 7 fold would tell us that it's had a run up. and it should retrace.
Nice point of you! Talk soon.