In my opinion the matter is really serious. Because a country essentially delegates the security of a huge-valued asset pile to a company. It's obviously not the first time it happens, but it signifies the continuation of the "trust mentality" that they can't get away from. Bitcoin comes to solve this, so in a more libertarian way of thinking, the USA should do their own custody and completely ignore third parties. Right now, the coins belong to Coinbase, not to the USA.
This is not unusual. Often times the government will delegate something to a private company because it is more specialized in dealing with those things and
doesis able to do so at a lower cost. However, in this case it would be more better to withdraw all of this from Coinbase. There is an overall benefit from that as Coinbase will have fewer coins, they already have too many stored with them.
Since they propose a bill for that, let’s just assume they already set all the measures to keep those billions in Bitcoin safe. They can’t just trust a 3rd party anymore. Even if it’s in an institutional wallet, we all know nothing is hack proof.
If they can keep the nuclear launch codes safe, they can definitely keep the small amount of Bitcoin that they own safe.