This is part of the nation state strategy regarding BTC. The US knows that Russia, China and other nations are working to accumulate BTC - China is now pushing for ownership of BTC through its people in Hong Kong and Russia is likely actively mining BTC.

The US knows that to win against BTC, it must adopt the same tactics. Telling BLK to buy up the BTC through open-ended trusts using boomer dollars is their way of taking ownership of the supply in a US jurisdiction and slowing the velocity of BTC. BTC held in trust by BLK cannot be used as money.