The companies like Microstrategy and Tesla might sell a portion of their coins when the price will reach high prices, they aren't average joe hodlers who will never ever sell because of a meme. If the price goes up 4 times relative to your investment, you can ensure going even by selling 1/4 of your stash - a pretty good move in a bull run. They are going to sell a portion of their coins close to the top, and hodl the rest for long term.
I think that if the price was crashing and they were given two options whether to buy more or sell their stash most likely they will make the calculation that it is on their best interest to reduce the impact of the crash and buy more in order to stabilize the market and protect their holdings that way than to sell everything they have and add more fuel to the fire.