That is called market manipulation, they talk about the market like it will do good and sell theirs and that's how they make their money, they expect everyone to get in so that they could get out without losing too much. This is just a method that they use so that they could profit the maximum.
Same concept goes when they want to buy as well, they make news both from their own mouths like this one but also they pay newspapers to talk badly about bitcoin as well and hope that everyone sells, so that they could buy cheap as well and reenter after they sell. This is just a method that whales use to manipulate the market and it is as old as time, nobody believes them anymore.
It would only be market manipulation if they are directly benefiting from it or at least trying to purposely do it. Otherwise, it's just making predictions without any substance behind them, both pretty bad. Though, most people don't care about either. Do we know how much JP Morgan are invested into Bitcoin, is that public knowledge? Since, if they did offload Bitcoin after claiming Bitcoin would reach x amount, then that would be clear manipulation, trying to artificially inflate the price, and then sell a large amount, and reinvest at a later date, rinse, and repeat.
Though, I'll be honest I don't know how effective the above title would be at increasing the price in the short term. After all, Tesla was bigger news recently, and that didn't really have much of a significant impact, at least not for long.