I can't agree with them about the 2K bitcoin. But even it fall to 2K, I will just buy more. If you don't need money and you are believing in crypto, then do nothing.
Everything had a major dips. Check the 'secure' gold for example and prices in '00 or <'70.
I can somehow agree with them with the 2000$ bitcoin as it is possible, I don't deem something as impossible just because adoption rate have dramatically increased as well as the support from the community. We must always remember that bitcoin is unpredictable, and the massive growth of users we have seen are from the get rich quick hype that newbies have jumped into and is just a fallacy. If it really does go down to 2000$, I would do the same.