No, it is not like that. No one is also forbidden to collect as much bitcoin as they can. Grayscale is doing it rightfully and there is nothing to see wrong with their purchases.
While the other companies are still in doubt of bitcoin, look at them, they are treating it as a habit or they have a plan to do this continuously before the bull run comes. They are just like us who believe in bitcoin but with the threat of 51% attack, the purchase is very far from that scene.
As others have mentioned earlier, 51% attack is not possible as they are just merely holding 2.x% of the entire marketcap of btc. Their move is actually very inspiring to other companies because this will give interest or confident to similar companies to invest also in btc. It also manifests that Grayscale has strong stand towards btc investments, which is good for crypto community.
Buying bitcoin and 51% attack have no relation so it's impossible to happen. It was explained very well by ETF. What can be connected to it is a possible plummet if they've decided to sell it all at once. But is that possible to happen? how they would do that? depends on them.
They are into digital investing so it's a basic thing to invest in bitcoin. As other companies would see their move, that will make them think why Grayscale do it like there's no tomorrow. I hope they wouldn't find the answer once bitcoin is already at the peak price.
