That’s most likely the case, but why would they dump their Bitcoin holdings? It doesn’t make sense.

If they ever decide to sell, it means they’ve found a valid reason to no longer see it as a good long-term investment, and that’s when others might follow, which could trigger a panic dump. However, history has shown that even when Bitcoin dumps, it eventually recovers. So it’s not something to panic about, it should be seen as an opportunity.

It seems completely foolish for an individual or institution to take such a decision when it comes to holding such a big dream. The possibility of this happening in reality is very low. I think that unless he or his company falls into some major disaster, there is no chance of such a situation. However, as an investor, we must be prepared for anything. When it comes to investing, we do not rely on anyone but rather invest in our own strength, which will create confidence.

If an institution or individual tries to sell a large part of Bitcoin, that is their own business. However, no one ever invests in Bitcoin with the intention of intentionally losing money. If MicroStrategy had such an objective, they would have had the opportunity to implement that objective long ago. But they did not do that, rather they are trying to accumulate more Bitcoin under their control so that they can own more wealth in the long run.

The chance of this happening in real life is low, but you said it yourself that "as an investor, we must be prepared for anything", and we're in a market that's unpredictable at some point.
For the record, most of the BTC holding of MicroStrategy is not owned by Saylor and Phong Le. So, there's a chance that the company could dump their bag if the investors requested it as an opportunity to take profit to avoid a situation like the Wall Street crash, which was triggered by the global depression, and a lot of people rushing to sell their shares
We can see MicroStrategy doing the same sell off before the market bloodbath just to accumulate the dip later.

Microstrategy might be amongst the top investors in bitcoin and hold some large amount of it in their portfolio, but I don’t think them selling off will have a significant lasting effect to the whole market. The percentage they hold is still nothing compared to the overall percentage of bitcoin mined so far and in circulation. It is not about them selling off that will affect the market a little bit but it’s about those that easily panic out of fear of what they might have foreseen to take such actions. Microstrategy are investors in bitcoin like any other company that has invested in it, if they wish to opt out they can but as a smart investor that they are, I don’t think they will do such a thing.

If MicroStrategy decides to sell all of its Bitcoins, it will likely impact on the market. The company holds over 500,000 BTC, which is a huge amount of liquidity. A swift sell-off could cause short-term instability, but the bigger problem would be if institutional investors follow suit.
That being said, I think it is more likely that if MicroStrategy decides to sell BTC, they will choose a more gradual approach, selling a relatively small amount.

Nobody is talking about a likely (if not the most likely) long term outcome: Eminent domain. Suppose the Lummis bill passes and the US decides to purchase ~1 million Bitcoin. How is it going to do that? On Coinbase? Hahahaha. That would run the price. What are the alternatives? Hint: Think like a government bureaucrat. You exercise the right of eminent domain and seize all of Microstrategy's Bitcoin. The government can do this as long as the seizure is for a public purpose and the government pays fair market value. The public purpose element is easy to meet: If Congress says it is in the public interest to purchase 1 million Bitcoin, then it is in the public purpose. Period. End of story. It does not matter that they could get the Bitcoin elsewhere. They can seize it as long as pay fair market value. That is fair market value as of the date of the seizure. This means the government can grab the Bitcoin without running the price. The company and its investors may cry foul, but this is how eminent domain has always worked.     

The fact is that not everyone has good knowledge in studying the Bitcoin trip itself because there are still many people out there who suffered losses when investing.
There is something wrong in understanding to enter the market so that when FUD affects a person's psychology will make them make the wrong decision..
Intelligent investors understand their pattern and they do not determine the direction of investment based on FUD, although sometimes they take advantage of the FUD conditions in making purchases because panic can be an advantage if it is able to be utilized and to be more certain to do a study before accumulating.

Usually it is investor behavior that does not have good experience or knowledge so that in certain conditions they are wrong in making decisions and in the end they suffer losses because they are unable to make previous analysis correctly.

This is correct. Before Saylor brought the idea of Bitcoin accumulation to the company, he himself was a holder who had studied the market and understood how it works. After taking him how many years of being a Bitcoin fan to get involved in it, now fully means they have studied everything and are prepared for the worst possible market condition. FUDs can't scare such institutional investment; instead, such companies can be the ones to trigger FUDs if they want to.

Never forget one thing and why some people can achieve maximum profits in the same market conditions, it is none other than they are able to see opportunities in the conditions of market chaos caused by the FUD we are talking about.
FUD does not always end negatively for people who are able to forgive the conditions because if this happens, usually bitcoin experiences a sharp decline and some people take advantage of these conditions to make large accumulations.

Investment is only about opportunities, besides the target of achieving the expected maximum profit, sometimes someone must have the skills to take advantage of existing conditions and more importantly avoid excessive panic