Not really of the assests, but rather of the value of those assets, measured in counter-valued fiat terms … but only on the books to date, since they are unrealized losses until they actually sell their BTCs.

That doesn’t mean that the situation is not worrying at some level for them, not only from the perception perspective, but also from the bookkeeping point of view. The bitcoins owned by the government allegedly came from the initial 150M $ bitcoin Trust established to give liquidity to the Chivo System. I say allegedly because, if my memory serves me well, the initial statements pointed in this fashion, but there is no explicit mention to all subsequent purchases. Even so, the bond likely has some bookkeeping rules to comply with, and standing at a loss of say those mentioned 40M $, even if only on the paper, may trigger some inner problems at some point in time.