Don't hear about these kind of predictions these are just opinion of the single person so it doesn't make any change in the market condition.Yes I am also think the bitcoin will hit $40000 or more but that soon is equal to how long nobody can answer that.
And also please remove $20000 from your mind which happened in bitcoin because of hype so which is not the maximim price and also the price not supposed to be in 2017 but it happened because of many factors.Just concentrate on the current price which is about $7450 at the moment.