I have heard crypto companies claim that they moved coins for custodial management operation, but it turned out they were selling. The Japanese Bitcoin treasury company might want to take profits; who knows?
It isn't impossible for a company to say they're doing custodian management operation yet selling, Coinbase Prime is an institutional desk for many things beside custody including OTC and financing.
Even if they sold, would they announce it? I don't think so.
The last time CEO confirmed the transaction was custodian management operation was in 13 august 2026 and transaction afterward should be considered not related to that statement.
Therefore I wouldn't be so confident to say that they are also doing custodian management this time around until the CEO himself stated otherwise.