Why would you want a Federal crypto reserve? (other than short term gains)

Cryptocurrency skeptic here (Hear me out).

When I first heard about the plan for a Bitcoin federal reserve I had a lot of feelings, but one thought keeps coming back : Who cashes out first?

The plan as I know it is that the Fed buys 1 million bitcoin (5% of the current bitcoin circulation, value at posting of $100 billion USD) over 20 years (est $5 billion/year). Justifications include funding federal programs with the "revenue". But the only way to get money from cypto is to sell it. So when the Fed even whispers about selling the reserve, wouldn't the price crash?

The top Bitcoin investors (who helped get the current president elected) have definitely thought about this scenario, so they definitely have a plan for capitalizing on their investment. The top 20 crypto holder control more than 19% of the bitcoin supply (not accounting for Nakamoto's estimated 5%), so this small group of finance professionals have significant control over bitcoin supply and demand. And the Fed must know that the investors know.

Looks like we have a Mexican standoff. Whoever sells screws over everyone who owns a bitcoin. If investors decide to sell, the US taxpayer is left $100 billion in the hole. If the president (this one or the next) or the senate becomes crypto bearish and decides to sell, the investors lose a lot of value.

The only reason I can see the Fed going through with this is to setup a legal framework that keeps the investors from screwing them over. Which the investors would hate as the whole point of cryptocurrencies was that no single entity (nation-state or otherwise) would have complete control over the circulation.

This isn't even considering the possibility of a fork or other rug-pull that would prevent the Fed from selling.

Does any of this seem plausible? I'm certainly no expert in finance or cryptocurrency so if anyone has a plausible reason why this Mexican standoff would not happen, I'll listen.