
It is kind of odd for such kind of wallet to have that kind of bitcoin held on a single wallet, let's assume that it is an exchange wallet which in this case is assumed to belong to coinbase but most exchange cold wallets are always multi-sig wallet for security reasons but this is an old wallet legacy address.
If you look at the transaction with this wallet address
1LQoWist8KkaUXSPKZHNvEyfrEkPHzSsCdI'm a bit sceptical about why will MicroStrategy send bitcoin to coinbase wallet, if they are doing an OTC transaction, it should be that it is the exchange wallet that should be sending bitcoin to the MicroStrategy wallet. Also, the assumed coinbase wallet just had only incoming transactions and not a single outgoing transaction which leaves me with the question that where will they have bitcoin to settle some institutional investors who subsequently withdraw or even trade bitcoin if that wallet belong to coinbase.
I am sure that it will be spread out eventually. Coinbase does like to move money around and they have so much money, like insane amount of money that it is normal for them to switch it around time to time for protection. When you have 3 billion dollars just on one account, I am sure that someone could spend a few million dollars to buy some computers (and a few million dollars worth of computers would have "some" power) then you could use even brute force, or any other way to crack into it.
I am sure it must be still near impossible but it is still better to be safe than sorry which is why they keep on moving these one by one, and then probably will spread it out.