Do you really believe that TESLA sold Bitcoin to prove liquidity? Is this a joke? How can someone genius like Elon blindly buy $1.5B and only a few months later start proving liquidity on a fraction of it?
The best way to sell a large amount of BTC without moving the price down is when there is equally large buy order.
I am not sure if the claim is true or not, but if such a buyer did show up it makes sense to sell and cash out.